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

Beyond the readOnly/idempotent annotations, the description discloses meaningful behavioral nuance: a valid signature establishes who signed and that bytes are unchanged, but 'does not establish that the claim inside is true.' This helps the agent set correct expectations and avoids overinterpretation of verification results.

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?

Three sentences, no redundant filler, and the core operation is front-loaded. Each sentence earns its place: what it does, when to use it, and what the result does and does not mean.

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 single parameter with full schema coverage and an output schema, so return details need no elaboration. The description covers operation, use case, and important interpretive caveats—everything an agent needs to invoke and interpret this tool correctly.

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%, so the baseline is 3. The description adds value by explaining how the receipt fields are used: re-deriving the content address from the canonical payload and checking the ed25519 signature. This gives semantic meaning to fields like canonical_b64 and signature_b64 beyond their names.

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 and resource: 'Verify a statement receipt' and goes further by explaining the mechanism—'re-derive its content address from the canonical payload and check the ed25519 signature.' This clearly distinguishes the tool from sibling statement-management 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?

The description gives clear context: 'Use it on a receipt a counterparty hands you.' It indicates the intended input source and scenario, though it does not explicitly name alternative tools or state when not to use it. This is a clear usage context but lacks formal exclusions.

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