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

Adds substantial behavior beyond the readOnlyHint: Ed25519 over an active self-custodied citizen key, base64url signature encoding, one preimage per outcome so a 'pass' signature cannot be replayed as a 'fail', and that issued_at is baked into the signed bytes. It confirms the read-only annotation and explains it creates nothing.

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?

Dense but front-loaded: the core purpose leads, followed by crypto/signing details and the read-only note. Every sentence carries weight, though the replay-protection and read-only sentences could be tightened slightly.

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?

No output schema, so the description must carry return semantics, and it does explain that the returned bytes plus issued_at must be sent together. It is complete enough for correct invocation, though the unexplained 'secret' parameter leaves a small gap.

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 40%. The description clarifies issued_at semantics (part of signed bytes, must be echoed) and implies verdict is the pass/fail being recorded, but listing_id and submission_id are never explained, and the 'secret' parameter is undocumented in both schema and description. Partial compensation only.

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: it builds the exact bytes a verifier signs to record a PASS/FAIL on one submission. It distinguishes itself from sibling 'signing_bytes' and 'record_outcome' by being a preimage builder, not a signer or recorder. An agent can tell what this returns without opening the 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?

Clearly establishes the context: use this so you 'sign what you fetched rather than what you assembled.' It also gives the operational rule that issued_at must be sent back with the signature. It does not, however, explicitly name a sibling alternative (e.g. signing_bytes) or a when-not-to-use condition.

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