Send Email

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

Annotations already indicate destructiveHint=true and readOnlyHint=false. The description adds valuable context beyond annotations: 'Requires html_body and/or text_body' clarifies a mandatory condition, and 'BLOCKED in read-only mode' discloses an execution constraint not inferable from annotations alone. No contradiction.

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?

Two short sentences, front-loaded with the core action, then a requirement and a critical constraint. Zero waste, perfectly concise.

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?

The tool has 14 parameters and an output schema, but the description covers the essential constraints (single, direct content, body requirement, read-only blocking). It does not explicitly guide toward sibling tools for batch/template needs, which would round out the context, but it is adequate for the complexity.

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 71%, so baseline is 3. The description reiterates the html_body/text_body relationship already present in the schema, but adds no new semantic detail about parameters. It does not clarify the remaining 29% of parameters beyond what schema 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?

The description clearly states 'Send a single email with content supplied directly', which is a specific verb+resource+scope. It implicitly distinguishes from sibling tools like send_email_with_template and send_email_batch by emphasizing 'single' and 'content supplied directly'.

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 implies when to use this tool (single, direct content) versus alternatives (templates/batch) through the phrase 'single email with content supplied directly'. However, it does not explicitly name alternatives or state when not to use them, so it falls slightly short of a 5.

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