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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds genuinely useful context beyond that: the operation is free and keyless, and it discloses the exact verification dimensions performed. It does not, however, describe the outcome shape (pass/fail flags vs. a certificate payload), which matters for a verification tool.

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?

One densely packed sentence that front-loads the action and enumerates the checks in a scannable list, followed by the cost/access note. No filler, though the single sentence is long enough that a reader must parse several clauses.

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-parameter read-only tool this covers the 'what' well, but with no output schema the description should indicate what a verification returns (e.g., boolean validity per check). That remains the main missing piece for an agent to interpret results.

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 both cert_id (spc_... format) and the optional document_sha256 are fully documented in the schema. The description reinforces their purpose ('whether a document is one it covers') but adds no format, encoding, or error-handling detail beyond the schema.

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?

A specific verb (verify/check) applied to a specific resource (Privi supplier certificate), with the exact claims being tested: untampered, not revoked, not expired, buyer-to-supplier approval, and optional document coverage. This clearly separates it from supplier_certs (listing) and supplier_cert_revoke (revocation), though no sibling is named explicitly.

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 context is implied by 'Check a ... certificate' and reinforced by the practical hint 'Free; no key needed', which removes an adoption barrier. There is no explicit statement of when to prefer this over supplier_certs or supplier_proof_inbox, and no prerequisites or exclusion conditions.

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