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

Annotations already declare readOnlyHint=false, idempotentHint=false, destructiveHint=false and openWorldHint=true, so the mutation profile is covered. The description adds only that a user-supplied code is involved; it says nothing about invalid-code behavior, code expiry, one-time use, or rate limits.

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 efficient sentence that front-loads the action and resource. It is appropriately sized for a two-parameter tool, though it could have spent a few more words on prerequisites without bloat.

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 exists, so the agent gets no information about return values, and the description doesn't mention them. With annotations covering the safety profile and the schema covering most parameter detail, the definition is workable but thin on prerequisites and failure behavior.

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 coverage is 50%: the code parameter is well documented in the schema ('Ask the user for it; never guess'), while email carries only format and pattern. The description maps to both parameters ('email address', 'verification code') but adds no format or validation meaning beyond that.

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 (Confirm) and resource (an email address) plus the mechanism (the verification code the user received). An agent can distinguish it from request_email_verification and resend_verification_email by inference, but the description never names those siblings explicitly.

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?

'With the verification code the user received' implies the prerequisite that a code must already exist, but the tool never states that request_email_verification must run first, nor when to prefer this over resend_verification_email or reverify. Usage is implied rather than prescribed.

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