Update an API key

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

Annotations already declare readOnly=false, idempotent=true, destructive=false, and openWorld=true, so the safety profile is covered. The description adds the ownership/authorization constraint and a deprecation warning, which are useful, but leaves the deprecation ambiguous rather than actionable.

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?

Short and front-loaded, with the core behavior stated first. The restating of the title in the opening line and the metadata trailer are slightly redundant but the body earns its space.

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 three-parameter mutation with full schema coverage and annotations covering safety and idempotency, and no output schema to explain, the description covers what an agent needs. Only the unresolved deprecation pointer leaves a gap.

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 id, name, and permissions are already documented, including the large permission enum. The description only names 'name and permissions' without adding format, replacement semantics, or validation detail, 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 (update), resource (API key), the editable fields (name and permissions), and the lookup key (by ID). It is distinguishable from siblings like create_api_key and delete_api_key, though it does not explicitly contrast with rotate_api_key, which also mutates a key.

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?

Provides a real prerequisite — the current user must own the key — and flags deprecation. However, the deprecation note is vague ('prefer the replacement operation if one exists') and names no alternative, and there is no guidance distinguishing this from rotate_api_key when a key's secret rather than its metadata needs to change.

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