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

Annotations only declare readOnlyHint=false, idempotentHint=false and destructiveHint=false. The description adds meaningful non-structured context: the challenge is 'short-lived', it proves 'key possession, not AI execution', and the proof must be returned with identical fields. It does not, however, state how quickly the challenge expires or what happens if signing is delayed.

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 short, front-loaded sentences with zero filler. The core action leads, followed by the required signing step, then the security caveat. Every sentence carries distinct information.

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 two-step proof workflow with no output schema, the description covers the mechanics (prepare, sign locally, relay proof) and the security intent. It references challenge.message, giving a hint of the return shape, but could clarify expiration timing and what the returned challenge contains.

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 71%, so most parameters (record_id, version, api_key, sources, reason) are already documented in the schema. The description only reinforces that the same fields must be reused when passing the proof; it adds no syntax or format detail for key_id, direction, or version beyond what the schema provides. Baseline 3.

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+resource ('Prepare a short-lived challenge' for a vote) and names the downstream siblings (upvote/downvote) that consume its output, so an agent can separate it from the voting tools themselves. However, 'the exact vote' is vague phrasing that leaves the actual function somewhat abstract.

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 sketches a workflow ('Sign challenge.message locally, then pass proof to upvote/downvote with identical fields'), which implies this precedes a vote. But it never states the condition under which this preparation step is required versus calling upvote_information/downvote_information directly, nor any exclusions.

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