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

With no annotations provided, the description carries the full burden. It adds useful behavioral context: 'Real result, no wallet' indicates simulation without requiring a wallet connection and implies no on-chain transaction is sent. It also discloses the output scope and the upgrade path. However, it does not explicitly state read-only safety, potential rate limits, or error behavior, leaving some gaps.

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 only two sentences, highly efficient, and front-loaded with 'FREE.' It packs all key information (output fields, no-wallet caveat, upgrade path) without any redundant words or repetition of schema details. Every phrase earns its place.

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?

Given the lack of an output schema, the description effectively enumerates the returned data (method, revert flag, risk level, predicted effect types) and the limitations versus the paid version. It also hints at the transaction context ('Real result, no wallet'). This makes the tool's behavior reasonably complete for selection and invocation, though it doesn't describe error cases or output formatting.

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 has 100% description coverage for all 5 parameters, so the baseline is 3. The tool description itself does not elaborate on parameter usage, but the schema already provides sufficient meaning for each field (e.g., 'to', 'data', 'chain', 'from', 'value'). Thus, the description adds no extra parameter semantics beyond the 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 clearly states the tool's function: it simulates a transaction and returns method, revert flag, risk level, and predicted effect types. It explicitly distinguishes itself from the sibling 'simulate' tool by noting it's the free tier with a limited output set, and mentions 'Real result, no wallet,' making the purpose unambiguous.

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 context on when to use this tool: it is the free version that returns core simulation results, and it explicitly points to the paid 'simulate' tool for full deltas and all risk flags. While it doesn't explicitly exclude other sibling tools like approvals or token_safety, the contrast with 'simulate' offers actionable guidance for choosing between the simulation variants.

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