attestation_verify

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

With no annotations, the description carries the full burden and mostly succeeds: it discloses the internal step order (canonical hash recompute, then signature check) and, critically, an explicit negative - it does not bind the supplied key to the claimed key_url or signer. That caveat is a real security-relevant trait. It stops short of top marks because it never says what happens on failure (exception vs. false result) and gives no guarantee about the hash algorithm convention.

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 tight sentences, each doing distinct work: what it verifies, how it verifies, and what it deliberately does not verify. The limitation is placed immediately after the mechanism, so the most decision-relevant caveat is front-loaded rather than buried.

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 nested-object, three-required-parameter verification tool with no annotations and no output schema, the description covers the verification semantics well but leaves the result contract unspecified - an agent cannot tell whether a failed signature check returns a boolean, an error, or a structured report. The absence of an output schema makes that gap more costly than it would otherwise be.

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 67%, so the baseline is around 3. The description restates the public_key format (64-char hex or base64) that the schema already documents, and clarifies that the key is caller-supplied rather than resolved, but adds nothing about the nested attestation fields or what 'body' must be (raw bytes, JSON, canonical form?).

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 (verify) and resource (ed25519 Attestation envelope) plus the exact mechanism: recompute the canonical hash, then verify the signature over the hash string. It does not name the sibling tools attestation_canonical_hash or attestation_inspect to distinguish itself, so it falls just short of the top tier.

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?

Usage is implied by the verb - an agent can infer this is the tool to run when it holds an envelope, a body, and a trusted key. The 'Does not verify that the supplied key belongs to the claimed key_url or signer' sentence functions as a partial scope exclusion, warning the agent not to use this for trust-chain validation, but no alternative tool is named for that case.

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