Resend email

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

Annotations already indicate a non-destructive mutation. Description adds that it applies to previously sent emails, but does not disclose potential consequences like duplicate sends or error behavior if email_id is invalid.

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?

Single sentence with no redundancy, front-loaded with the action and resource.

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 two-parameter tool with full schema coverage, the description provides purpose, usage context, and an example. Minor gaps like error handling are not critical for selection/invocation.

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 covers both parameters with descriptions (100%), so baseline 3. Description clarifies email_id refers to a previously sent email, adding slight value, but adds nothing about dispatch_now beyond schema.

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 action ('Resend') and resource ('previously sent email'), with examples (invoice/verification) that clearly distinguish it from sibling tools like resend_client_verification and get_email.

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?

Provides clear usage context ('a previously sent email... that never arrived') indicating when to use, but does not explicitly exclude alternatives or mention when not to use.

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