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

Annotations are minimal (only hint flags), so the description carries much of the behavioral burden. It adds valuable lifecycle context: codes expire in 10 minutes and retrying an expired code is the wrong move. It does not mention what happens on incorrect codes or whether a successful verification returns a specific response, but the key expiry and retry behavior is covered.

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 sentences, front-loaded with the core purpose, then the prerequisite, then expiry and fallback guidance. Every sentence earns its place with no filler or repetition.

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 simple 2-parameter verification tool, the description covers when to call it, what to pass, and what to do on failure or expiry. It lacks only explicit output/response expectations and any mention of the confirm_recovery sibling, but the token parameter is covered by the schema.

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%, so the baseline applies; the schema already explains both code and token. The description reinforces that code is the 6-digit email code but adds little beyond what the schema already provides.

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?

Description states a specific verb and resource: confirm the 6-digit code sent to the agent email, and frames it as the prerequisite before email recovery works. It also distinguishes itself from sibling resend_email_code by positioning that tool as the fallback for expired or missing codes.

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?

It explicitly says this must be used before email recovery works and gives the alternative action for expired or never-arrived codes. It even supplies a negative rule: do not keep retrying the old code, which prevents an agent from looping on a dead code.

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