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

With no annotations provided, the description carries the full burden of behavioral disclosure. It covers key traits: costs 1 credit, returns PASS only on exact byte-for-byte match, enumerates the exact fields checked, and clarifies the trust model (no trust in issuer/key). It does not explicitly state what happens on mismatch or whether the operation is read-only, but the nature of a verification/recompute tool makes this implicit.

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?

The description is succinct and front-loaded with the core action. It efficiently packs essential information: the verification approach, trust model, cost, and the strict PASS condition with a field list. No superfluous words or redundant details.

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?

The tool has two complex object parameters, no annotations, and no output schema. The description covers the primary behavior, cost, and success criteria, and it distinguishes the tool from siblings. However, it lacks an explicit comparison to verify_certificate (beyond cost) and does not describe the failure response or edge-case behavior, which would make it fully complete.

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 100% for both parameters. The schema already describes certificate as 'The CausalCertificate object claimed by the issuer' and canonicalInput as 'the original incident body that produced the certificate — the same JSON originally posted to submit_incident or submit_otel_trace.' The tool description adds no new parameter-level details beyond the schema, so baseline 3 is appropriate.

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 clearly states a specific verb and resource: 'Independently re-derive a CausalCertificate from its canonical input and compare byte-for-byte against the claimed certificate.' It also distinguishes itself from the sibling verify_certificate by emphasizing it is the 'strongest verification path' requiring no trust in issuer, making its unique purpose unambiguous.

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 description provides clear context for when to use this tool over alternatives: it is the strongest verification path and requires no trust in issuer or signing key. It also notes cost equivalence with verify_certificate, implying it can be used as an independent check. However, it does not explicitly state when NOT to use it or name an alternative like 'for standard verification, use verify_certificate'.

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