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

With no annotations, the description must disclose side effects and constraints. It does mention the need for a Proof account and the authentication flow (start_login) before this tool can be called, which is useful. However, it does not describe what happens on success or failure, whether the operation is idempotent, or any rate limits. It also does not clarify that the email is sent to the subject's registered email address. It adds some value but lacks depth.

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?

The description is concise, with the primary purpose stated in the first sentence. The second sentence provides necessary authentication context. There is no fluff or repetition, though the access guidance is slightly verbose with the 'Claude Code: /mcp → Authenticate' detail. Overall it is well-structured and front-loaded.

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?

The tool is simple with a single parameter, so the description need not be extensive. It covers the essential requirement of authentication and identifies the recipient (subject of a verification request). It lacks details about return values or error handling, but since there is no output schema and the operation is straightforward, the description is adequate for an agent to call it correctly.

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?

The schema already describes the only parameter (id) as 'Verification request ID' with 100% coverage. The description does not add any additional detail about how to obtain the id or what format it should be in. Baseline of 3 is appropriate since the schema covers the parameter and the description does not contradict it.

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 clearly states the tool sends an email notification to the subject of a verification request. The verb is specific ('send'), the resource is explicit ('email notification to the subject of a verification request'), and it distinguishes from siblings like send_account_email or resend_verification by specifying the recipient and context.

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 does not explain when to use this tool over alternatives such as send_account_email or resend_verification. It only mentions authentication requirements, which is about how to use the tool, not when. No context about prerequisites (e.g., that a verification request must exist) or when this is the appropriate action is provided.

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