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

Annotations already cover read-only and idempotency, and the description adds genuinely new behavior: each call re-signs with a fresh issued_at, the receipt is verifiable offline via a named key endpoint and recipe, it should be retained, and it proves what was recorded rather than correctness. That is exactly the context annotations cannot carry.

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?

Front-loaded with the core action and scope, and every subsequent clause (contents, verification, caveat, freshness) carries information. The first sentence is long and comma-heavy, which costs some readability but no content is wasted.

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?

With no output schema, the description compensates by enumerating the receipt's fields and explaining how to verify it independently, plus the important caveat about what it does not prove. An agent has everything needed to call it and use the result.

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 the single request_id parameter is fully documented in the schema, so the baseline applies. The description only adds an implicit precondition (the request must have ended) rather than any format or sourcing detail 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?

States a specific verb and resource ('Get a signed receipt for a Request') and immediately scopes it to ended requests, then enumerates exactly what the artifact contains. An agent can distinguish this from get_request or request without opening either schema.

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 precondition 'a Request that has ended (completed or declined)' tells the agent when this tool applies, which is real usage guidance. It stops short of naming an alternative for in-flight requests (e.g. use get_request), so it is clear but not exhaustive.

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