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

Annotations already mark this as read-only and non-destructive. The description adds valuable behavior beyond that: it confirms the accepted authentication mechanisms and explicitly discloses that the secret is not echoed. This is useful context for an agent deciding whether to call the tool safely.

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 short sentences, each carrying distinct meaning: what the tool confirms, how authentication is expressed, and a security-relevant limitation. The most important verb and resource appear first, with no redundant framing or filler.

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 zero-parameter, read-only verification endpoint, the description is complete. It names the exact endpoint, lists accepted credentials, and clarifies that the secret is not echoed. Annotations cover the safety profile, and no output schema means the description does not need to document return fields.

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?

There are no input parameters, so the baseline is 4, and the description goes further by explaining the caller-key semantics: PDF_TEXT_API_KEY, Authorization: Bearer, and the X-API-Key alias. This gives an agent clear guidance on what credential is being verified even though the schema is empty.

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 states a specific action: confirming an API key via the /keys/verify endpoint. It clearly distinguishes verification from key lifecycle operations like issue_key, revoke_key, and rotate_key among the siblings. The title also disambiguates which product context this key belongs to.

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 description implies the tool is for checking key validity, and the GET path suggests a non-mutating verification call. However, it does not explicitly state when to use it versus related tools such as health or the key-management siblings, nor does it mention any exclusion cases.

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