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

Annotations already establish readOnlyHint=true, so safety is covered. The description adds genuinely useful behavioral context beyond them: the secret is never returned, telling the agent what the result will and will not contain for a credential-adjacent resource.

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 short sentences, front-loaded with what is fetched first, then the secret-exclusion caveat and endpoint. Every clause earns its place with no redundancy.

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?

No output schema exists, and the description partly compensates by stating the secret is omitted from the response. For a single-parameter read tool with readOnlyHint, that is nearly complete, though it does not describe the shape of the returned metadata or error behavior.

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% with a single documented id parameter, so the baseline is 3. The description only restates 'by id' and adds no format, source, or example 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?

States a specific verb and resource ('Get a single API key's metadata by id'), which clearly separates it from the sibling list_api_keys (single vs list) and from portkey_get_virtual_key (API key vs virtual key). The endpoint mapping (GET /api-keys/{id}) reinforces exactly which resource is fetched.

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?

The phrase 'by id' implies this is the lookup-by-identifier path as opposed to listing, but there is no explicit when-to-use guidance or naming of the alternative (e.g., use portkey_list_api_keys when you don't have an id). Usage is inferable but not stated.

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