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

Annotations already declare readOnlyHint=false, idempotentHint=false and openWorldHint=true, so the agent knows this has side effects and reaches outside the system. The description adds the useful two-step verification workflow, but says nothing about rate limits, code expiry, or whether repeated calls invalidate prior codes.

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, no filler, and the action is front-loaded ahead of the follow-up instruction. Every sentence carries information the agent needs.

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 and a single input param, so the description need not explain returns. It covers the action and the subsequent step, which is what the agent needs. Minor gap: no mention of what the response contains or how long the code is valid.

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 0%, but there is only one parameter and the schema enforces format=email with a regex pattern, so the shape of the input is unambiguous. The description only says 'an address', adding little beyond the schema; acceptable with a single well-constrained param.

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+resource: emails a verification code to an address. It also names the follow-up sibling verify_email, so the agent can place the tool in the verification flow. It does not explicitly distinguish itself from request_phone_verification, the closest alternative.

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?

Gives clear when-to-use context ('so it can be used for notifications or workflows') and prescribes the next step: ask the user for the code, then call verify_email. It stops short of stating exclusions, prerequisites, or what to do if the email never arrives.

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