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

Annotations only declare readOnly=false, destructive=false, idempotent=false and openWorld=true; the description goes well beyond them by disclosing real side effects — certificate issuance naming both companies, evidence fingerprints sealed on-chain, a public verify page and badge — and the auth requirement. It does not address the non-idempotent hint (e.g. whether deciding twice issues a second certificate), leaving one meaningful gap.

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?

A single front-loaded sentence covering the primary action, with the alternate branch and the auth prerequisite following in the same breath. The nested parenthetical about certificates and fingerprints is dense but each clause 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?

With no output schema, the description compensates by explaining what approving produces (certificate, on-chain seal, public verify page). It still omits the response shape — whether a certificate ID or verify URL is returned — and whether a decision can be reversed, which matters for a non-idempotent mutation.

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%, so sub_id, approve and reason are already fully documented, including 'true issues the certificate; false rejects' and the rejection-reason rule. The description restates rather than extends this, so the baseline 3 applies.

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 pair and resource ('Approve a supplier's proof ... or reject it with a reason') and spells out the outcome of each branch, so an agent can separate it from supplier_proof_submit and supplier_proof_inbox without opening a 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?

Implies the decision context clearly and states a prerequisite ('Requires the organization API key') plus the conditional requirement that a reason is needed for rejection. It does not, however, name alternatives such as supplier_cert_revoke for post-approval revocation, nor say what to do if the proof was already decided.

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