Settings: set

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

Annotations already declare destructiveHint=true and readOnlyHint=false, so the safety profile is known; the description still adds real value by disclosing the partial-update semantics ('keeps the rest'), the value format ('booleans take true or false'), and the fact that some changes (sign-ups, email confirmation, admin role) apply without a further prompt. It stops short of describing return values or reversibility, hence not a 5.

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: purpose first, alternatives and value syntax next, destructive-confirmation caveat last. No filler and nothing 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 2-parameter mutation with full schema coverage and annotations carrying the destructive/read-only profile, the description supplies everything missing: key examples, boolean formatting, the CORS sibling route, and a confirmation requirement. No output schema exists, so return values need not be explained.

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 coverage is 100%, so the baseline is 3, but the description adds meaning the schema does not: concrete example key names and the fact that booleans are passed as true/false even though 'value' is typed as a plain string. That clarifies the loose typing the schema leaves implicit.

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 precise verb+resource pair ('Set a single project setting') and immediately scopes it against the sibling it is not: 'For CORS origins use settings_cors_add'. The examples of valid keys (allow_registrations, default_role_id, ai_mode, payment_success_url) and the reference back to settings_get make the target of the operation 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?

It names the discovery path ('named as in settings_get'), the sibling alternative for the CORS case ('For CORS origins use settings_cors_add'), and an explicit pre-condition to confirm with the user before running. An agent knows both when to pick this tool and when to route elsewhere.

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