Send email

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

Annotations already indicate destructiveHint: true, but the description adds behavioral context: 'A copy is filed in Sent automatically' and 'This delivers real mail — confirm before running.' This provides meaningful detail beyond the annotations about automatic filing and finality.

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?

The description is three sentences, front-loaded with the action, and contains no unnecessary words. Every sentence adds value: purpose, automatic filing, and destructive warning.

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?

Given the tool's complexity (9 parameters, no output schema, sibling tools), the description is partially complete. It covers the main purpose and destructive nature, but lacks guidance on parameters and when to use alternatives like 'create_draft'. It is adequate but has clear gaps.

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?

The description does not mention any parameters or add meaning beyond the input schema. With 9 parameters and only 56% schema description coverage, the description should compensate by explaining key parameters like 'to', 'subject', or 'account', but it does not.

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?

The description clearly states 'Send an email from the account via Gmail SMTP', specifying the verb (send), resource (email), and context (Gmail SMTP). It distinguishes from the sibling tool 'create_draft' by noting that this sends real mail, not a draft.

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 warns 'confirm before running' but does not provide explicit guidance on when to use this tool versus alternatives like 'create_draft' for drafts. It lacks context for appropriate versus inappropriate use.

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