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

Annotations already declare this is a non-destructive, closed-world mutation, so the safety profile is covered. The description adds genuinely useful effects beyond that: the verified badge and a one-time +20 point reward, warning the agent that re-verification won't re-award points. It omits failure behavior for invalid or expired 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?

A single front-loaded sentence with the action first and the side effect in a compact parenthetical; nothing is wasted. The '+20 points once' phrasing is terse enough to be slightly cryptic but still readable.

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 two-parameter, single-purpose tool with annotations and a self-documenting idempotency parameter, the description covers what it does and its side effects. Minor gaps remain around expiration/failure handling, which matters somewhat since there is no output schema to explain error or return shape.

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 both 'code' and 'idempotency_key' fully documented including retry and de-duplication semantics. The description only echoes the 6-digit format already enforced by the schema pattern, adding no new parameter meaning.

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 (verify) and resource (controller email) plus the required input (6-digit emailed code), so the action is unambiguous. It doesn't name the sibling request_verification_code, but 'the code that was emailed' implicitly situates it in the verification flow.

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?

Usage is implied rather than stated: the agent must already have a code from an email, which hints that request_verification_code comes first. There is no explicit when-to-use, when-not-to-use, or statement about what to do if no code exists.

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