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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is clear. The description adds valuable behavioral context beyond annotations: it discloses the address format limitation (legacy only, bech32 unsupported) and the signmessage format requirement. This is useful because it tells the agent what inputs will fail. It doesn't describe error behavior or return format, but the output schema exists and the annotations cover the safety profile, so a 4 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?

The description is three sentences with zero waste. The core purpose is front-loaded in the first sentence, the critical limitation is in the second, and the use case is in the third. Every sentence earns its place, and the structure is ideal for an agent scanning for relevance.

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 clear purpose, full schema coverage, an output schema, and annotations covering safety. The description adds the key contextual detail (address format limitation) that an agent needs to avoid failed calls. It doesn't explain the return value, but the output schema exists, so that's not required. The only minor gap is that it doesn't mention what happens when verification fails (e.g., returns false vs throws an error), but this is a minor omission given the output schema and annotations.

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%, so the schema already documents all three parameters (address, message, signature) with descriptions. The tool description adds some context by explaining the address format constraint (legacy vs bech32) and the signmessage format, but it doesn't add significant meaning beyond what the schema already provides. Baseline 3 is correct when the schema does the heavy lifting.

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: verifying whether a message was signed by the private key of a Doichain address. It specifies the exact format (signmessage format) and explicitly distinguishes it from other operations. The title 'Verify a signed message' is reinforced by the description, and the tool is clearly differentiated from siblings like hash_text or get_transaction.

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 states when to use this tool: to confirm that a statement really comes from the holder of an address. It also provides a clear exclusion: bech32 addresses (dc1q...) are not supported, only legacy addresses (M... or N...). This gives the agent actionable guidance on when to use it and when not to, which is more than most tool descriptions provide.

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