cancel_email

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

No annotations are present, so the description carries the full burden. It does disclose one genuine behavioral constraint — the operation only succeeds before the email is sent — but omits whether cancellation is reversible, what happens if the email already went out, required permissions, and what is returned.

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 no filler; the operation and its timing constraint are stated immediately.

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 one-parameter mutation with no annotations and no output schema, the description is adequate but thin: it never says what a successful call returns (e.g. the cancelled email) or how an already-sent or unknown id is handled.

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%; the single 'id' parameter is already documented as 'Email id returned by send_email'. The description adds no format, source, or lookup guidance beyond that, so the baseline 3 applies.

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 (Cancel) and resource (a scheduled email) with a temporal scope ('before it is sent'), which is more precise than the bare name. It does not, however, distinguish itself from siblings like send_email or update_email by naming an alternative or a precondition.

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 gives no when-to-use framing, no prerequisites (e.g. the email must still be in a scheduled state), and no alternatives. An agent must infer that this is the counterpart to send_email and only applies to pending mailings.

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