Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations, the description carries the full burden. It conveys that the tool performs estimations (read-only) and lists actions, but does not explicitly state that no transaction is signed or submitted. It does add useful context about credits and response headers, which is a behavioral trait. Still, the lack of an explicit read-only/safety disclosure keeps it from a higher score.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is front-loaded with a clear purpose, but the credits section is excessively long and repetitive, listing the same credit values for multiple actions. This violates the principle that every sentence should earn its place. The core action list is useful, but the redundancy makes the description bloated and less scannable.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

The tool has 11 parameters and 5 distinct actions, but the description does not guide the agent on which action to choose for a given scenario. The schema hints at required parameters per action, and the action names are self-explanatory, but without an output schema or action-selection guidance, the description is only minimally complete.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100% and each parameter already includes detailed descriptions, including action-specific requirements. The tool description's action list duplicates some of this information (e.g., which action requires 'data') without adding new meaning beyond the schema. Therefore, it meets the baseline but does not elevate it.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description opens with a specific verb-resource pair: 'Get fee recommendations and estimate gas costs for EVM blockchains.' This clearly distinguishes the tool from its siblings (UTXO, XRP) by explicitly scoping to EVM. The subsequent action list enumerates concrete operations, leaving no ambiguity about what the tool does.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description provides clear guidance on when to use the tool: 'Use this before preparing or signing a transaction to determine appropriate gas parameters.' This gives a concrete context. However, it does not mention alternatives or explicit when-not-to-use scenarios, though the sibling tool names (UTXO/XRP) implicitly differentiate by chain type.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations provided, the description carries the full burden. It discloses the two actions, includes credit costs per action/blockchain, and notes that credits are indicative and actual costs are returned in response headers. This adds meaningful behavioral context beyond the schema, though it doesn't explicitly state read-only behavior or side effects.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is front-loaded with the main purpose in the first sentence, followed by usage guidance and a structured action list. The credits section is somewhat verbose but serves a purpose (cost transparency). Overall, it's well-organized and each section earns its place, though it could be slightly more compact.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

The description covers the tool's scope, use cases, available actions, and cost information, which is solid for a fee-recommendation tool. It lacks an output schema but the actions imply the return type. The description is sufficiently complete given the tool's complexity, though it could clarify the meaning of fee tiers or the return structure.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100% and each parameter has a description. The tool description adds action-to-parameter mapping (e.g., feeRatePriority and confirmationTarget are 'estimate-transaction-smart-fee only') but this is also present in the schema. The description doesn't significantly augment the parameter semantics beyond what the schema already provides, so baseline 3 is appropriate.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the tool's purpose: 'Get fee recommendations for UTXO blockchains' and lists the specific blockchains (bitcoin, bitcoin-cash, litecoin, dogecoin, dash, zcash). It also differentiates from sibling tools by naming the UTXO scope, which contrasts with the EVM and XRP siblings.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description provides explicit usage context: 'Use this before preparing or signing a transaction to determine the appropriate fee rate.' It also breaks down the two actions and their specific use cases. However, it does not explicitly mention when to avoid this tool or name alternative tools, so it falls short of a 5.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

No annotations are provided, so the description carries the full burden. It discloses credit costs and that actual credits are in response headers, which is useful. However, it does not describe the return format or any side effects, though as a read-only fee tool this is less critical.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is concise and front-loaded with the purpose. It includes credit info as a separate block, which is relevant but could be considered extraneous. Overall, it is efficient with no fluff.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

The tool is simple with one required parameter and no output schema. The description gives network options and credit costs, but does not explain what 'fee recommendations' includes or the structure of the response. For a minimal fee tool, this is adequate but has gaps.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%: both 'network' (with enum) and 'context' are fully described in the schema. The description only repeats the network names, adding no new parameter semantics. Baseline of 3 is appropriate.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the tool's function: 'get fee recommendations' for XRP, with specific network options. It distinguishes itself from sibling tools like blockchain_fees_utxo and blockchain_fees_evm by explicitly naming the chain (XRP) and supported networks.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description implies usage: when you need fee recommendations for XRP on mainnet or testnet. However, it does not explicitly state when to prefer this over sibling fee tools or system_info, nor does it mention exclusions or alternatives.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations provided, the description carries the full burden of behavioral disclosure. It clearly states this is a documentation-only tool with no API call and no credit consumption, which is a key behavioral trait. It also lists the detailed coverage of each action, giving a good sense of what the response will contain. While it doesn't describe response format or pagination, the tool is a simple reference lookup, so the disclosure is adequate.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is effectively structured with a leading one-line summary followed by a bulleted list of actions. Each bullet is concise and informative, with no redundant or filler content. It packs a lot of useful detail into a compact format, making it easy to scan and understand.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

The tool has a simple interface with only one required parameter, and the description covers all possible enum values with detailed context. It also conveys the crucial fact that no credits are consumed, which is important for cost-aware agents. No output schema exists, but the description clearly indicates what type of information is returned for each action, making the tool fully understandable.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The input schema already provides 100% coverage with descriptions for both 'action' and 'context', so the baseline is 3. The tool description adds substantial meaning beyond the schema by detailing exactly what content each enum value provides (e.g., errors includes HTTP status, error code, message; callbacks includes retry strategy and HMAC). This goes above the schema's simple 'Reference topic to retrieve'.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description opens with 'CryptoAPIs reference documentation — no API call, no credits consumed,' which precisely defines the tool as a documentation lookup rather than an operational API call. It then enumerates five distinct reference actions (blockchains, errors, credits, callbacks, limits), each accompanied by a brief scope. This clearly differentiates it from sibling fee-related tools like blockchain_fees_utxo/evm/xrp.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description explicitly notes that no API call or credits are consumed, signaling that this tool is for retrieving reference information, not for executing transactions. Each bullet item specifies the kind of information retrievable, such as error tables, credit costs, and webhook mechanics, giving implicit when-to-use guidance. It does not explicitly mention alternatives, but sibling tools are fee-specific, so the usage context is clear.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.