GhostKey — Route Paid APIs with x402

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

Annotations already carry the safety profile (readOnly, idempotent, openWorld, non-destructive), lowering the bar. The description adds behavioral value with 'currently' and 'staged,' signaling the catalog is dynamic and includes not-yet-available paid families. No contradiction with annotations.

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?

A single front-loaded sentence with the verb first and zero filler. Every word ('currently', 'exposed', 'staged') earns its place by adding scope or timing information.

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?

For a 0-parameter read-only discovery tool with a rich annotation set, nothing an agent needs to invoke it correctly is missing. Safety and idempotency are covered by annotations, and the return value (a list of tools/families) is self-evident from the description.

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 tool has zero parameters, so the description bears no burden of explaining inputs — baseline 4 applies. The description's specification of what gets listed further orients the agent beyond the empty schema.

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 uses a specific verb ('List') and a concrete resource ('GhostKey's currently exposed tools and staged paid families'). The scope clearly distinguishes it from siblings ghostkey_policy, ghostkey_quote, and ghostkey_status, which concern specific individual concerns rather than a catalog of available tools.

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?

Usage is implied: an agent needing to discover what tools exist would naturally call this. However, the description gives no explicit when-to-use or when-not-to-use guidance, and it never references the sibling tools, so routing depends on inference rather than stated direction.

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?

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and non-destructiveness. The description adds no extra behavioral context beyond confirming this is a read-only policy retrieval. With comprehensive annotations, the neutral score is appropriate.

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?

A single sentence that front-loads the action and precisely lists the policy domains. There is no wasted wording or unnecessary repetition.

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?

For a no-parameter, read-only policy lookup tool, the description is complete: it names the resource and the three policy areas. Annotations cover the behavioral profile, and no output schema is required for such a straightforward retrieval.

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?

There are zero parameters, so there is no parameter semantics burden on the description. The description does add useful context about the policy categories returned, but no parameter documentation is needed.

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 uses a specific verb ('Return') and names a clear resource: GhostKey operating, payment, and upstream-rights policy. It enumerates the exact policy domains, making the tool's purpose distinct from sibling tools like catalog, quote, and status.

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 intended use is implied: use this tool when you need GhostKey's policy content. However, it does not explicitly discuss when to prefer it over sibling tools or mention any exclusions, so the guidance is only implicit.

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?

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and non-destructive behavior. The description adds useful context by indicating that the tool explains how to obtain pricing rather than executing the quote itself, and it emphasizes the 'fresh live' challenge requirement. No contradiction with annotations exists.

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 a single sentence with no filler, and the core task is front-loaded. It is concise and easy to parse, though some additional parameter guidance would improve its completeness.

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?

For a low-complexity tool with read-only and idempotent annotations, the description covers the core purpose and safety profile. However, it lacks parameter semantics and sibling differentiation, so an agent has to infer how to actually invoke the tool with a capability value.

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 only parameter, capability, is completely unexplained. Schema description coverage is 0%, and the description never defines what capability values are valid, what they mean, or how they affect the resulting explanation. An agent cannot reliably populate this parameter.

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 states a specific verb ('Explain') and a specific resource/purpose ('authoritative pricing from a fresh live x402 402 challenge'). It is distinguishable from sibling tools like ghostkey_catalog, ghostkey_policy, and ghostkey_status, though the protocol jargon is unexplained.

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 phrase 'from a fresh live x402 402 challenge' implies the intended scenario for this tool. However, there is no explicit guidance about when to use this tool versus ghostkey_catalog, ghostkey_policy, or ghostkey_status, and no exclusions or alternatives are named.

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?

Annotations already declare this as read-only, idempotent, open-world, and non-destructive, so the description does not need to repeat those. It adds one behavioral clue — 'always-on SqueezeOS x402 authority' — suggesting the call is always available and relies on some authority, but the meaning of that authority is left unexplained.

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 a single, front-loaded sentence with no redundant filler. The authority clause adds some useful context, though it is slightly jargon-heavy and could be clearer.

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?

For a zero-parameter, read-only status tool, the description is largely sufficient: the agent knows what to call and why. The lack of an output schema is not a major issue for a status report, though a bit more detail about what the status contains would improve completeness.

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 tool has zero parameters and schema coverage is 100%, so parameter documentation is already complete. The description does not need to explain any fields, and no gap exists for it to compensate for.

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 uses a specific verb ('Report') and a clear resource ('GhostKey status'), so the agent knows exactly what action this tool performs. It is also clearly distinct from sibling tools that cover catalog, policy, and quote, since status is a separate concern.

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 this is the tool to call when GhostKey status is needed, but it gives no explicit guidance about when to prefer it over siblings or when not to use it. The phrase 'always-on' hints at availability, but no alternative routing or exclusion criteria are stated.

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