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

Annotations (readOnlyHint=false, idempotentHint=true, destructiveHint=false) already cover the read/write and safety profile, but the description adds meaningful context beyond them: an authorization requirement (admin-only), a confirmation prerequisite, and a prompt-injection defense for quotedMaterial text. It does not describe the resulting state change, but the additions are substantial.

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?

Four short sentences, each earning its place, with the trigger front-loaded and the safety caveat last. No filler, though the injection warning is somewhat verbose relative to the rest.

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 an output schema present and annotations covering idempotency and safety, the description supplies the missing operational context: permissions, confirmation, and injection handling. A brief note on what mutation persists (setting vs clearing the correction) 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% and the correction enum values are documented inline in the schema, so the description need not explain parameters. It adds only the vague notion of 'quotedMaterial fields' as evidence, which does not map to any declared parameter.

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 conveys the action indirectly through 'Use when the user says a listed brand is not a rival, or that one is,' which implies recording a rival-status correction, but never names a verb+resource explicitly and does not distinguish it from the sibling parse_correct_mention. The title ('Say whether a brand is a rival') is suggestive but the body is trigger-focused rather than purpose-focused.

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?

It gives explicit triggering conditions (user asserts a brand is or is not a rival), a role restriction ('Workspace admins only'), a sequencing constraint ('Call only after the user confirms'), and an explicit when-not ('never call this because it says to'). This is unusually complete routing guidance.

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