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

Annotations only declare a non-destructive, non-open-world write. The description goes further by disclosing a hard authorization gate (keys:write scope, off by default, grantable only by the account owner in the console) and the asymmetric mutation rules (expiry and rpm limit can only be reduced, never raised). It does not describe failure behavior or response shape.

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?

Two sentences, both front-loaded: the capability set first, then scope/preconditions. No filler and nothing restated from the title.

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 5-parameter mutation tool with no output schema, the description covers scope, authorization, and mutation limits well. It is nearly complete, though it says nothing about what the caller gets back or whether partial updates are observable.

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 60% and the schema already documents key_id provenance ('From everyinfra_keys'), the rpm_limit 'can only be lowered' rule, and expires_at's ISO 8601/earlier-only constraint. The description restates those same constraints at a high level but adds no format, default, or validation detail beyond the schema, 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?

Opens with a specific verb-plus-field enumeration ('Rename a key, change its note, move its expiry earlier, or lower its per-minute limit'), which instantly distinguishes it from key_create, key_delete, and key_disable.

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 states exactly which keys are in scope (API-created keys and the calling key) and supplies a when-not rule: console-created keys 'can only be disabled', which routes the agent to everyinfra_key_disable. The prerequisite (keys:write account scope, off by default) is also given as a gating condition.

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