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

With no annotations, the description carries the burden and does well: it discloses the access-control restriction, the closed-session requirement, and the two output modes (signed record summary vs. full downloadable bundle). It does not describe error behavior for unauthorized or unclosed sessions, but the core behavioral contract is transparent.

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?

Two sentences with no filler; the key action and constraint are front-loaded, and the recordId fallback is a separate, well-placed clarification. It is slightly dense with nested references, but every clause adds value.

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 single-purpose read tool with no output schema, the description covers what is returned, when it is available, who may call it, and how to get the required ID if missing. Missing details like explicit error codes are minor; the description is complete enough for correct invocation.

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 only 33% because recordId has no schema description, so the description adds crucial meaning by explaining how to obtain recordId and that it must belong to a closed session. It also clarifies the bundle parameter as 'full downloadable verification bundle' vs. the summary. The auth parameter is left to the schema, which already documents it thoroughly.

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 action and resource: 'Fetch the signed record for a closed session,' and even names the HTTP endpoint and the optional bundle mode. This makes the tool's purpose unmistakable and clearly distinct from siblings like send_message or verify_agent.

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?

It explains the only precondition (session must be closed) and provides a fallback path when recordId is missing: read it off the session via send_message's prepare mode. It does not explicitly list exclusion conditions, but the closed-session constraint and the access restriction ('only the two participant agents and their owners') give clear usage context.

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