Email an attendee

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

Annotations already indicate this is a non-read-only, non-idempotent, destructive operation, and the description's 'send' wording aligns with that. The description adds valuable behavioral context beyond annotations by specifying the rate limit (5 per 5 minutes) and the one-off nature of the email, which helps the agent plan around side effects and retries.

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?

Three short sentences, no filler, with the primary purpose front-loaded. Each sentence adds distinct value: what the email is for, the required input context, and the rate limit. This is a model of concise, structured tool documentation.

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 3-parameter tool with a complete input schema and an output schema, the description covers everything needed for correct invocation: purpose, content examples, the prerequisite attendeeId source, and rate limiting. Side-effect expectations are covered by annotations. There are no missing details that would prevent an agent from calling the tool safely.

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%, so the schema already documents attendeeId, title, and content sufficiently. The description repeats the attendeeId source ('from appointment details') and gives examples of content types, but adds little beyond the schema's own descriptions. Baseline 3 is appropriate because the schema does the heavy lifting.

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 states a specific action ('send a one-off email') and a specific resource ('to an attendee'), with concrete examples of acceptable content. This clearly distinguishes it from sibling tools like book_appointment or send_routing_form, which involve different workflows.

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 clear context for when to use the tool: one-off emails such as follow-ups, preparation notes, or directions. It also highlights a prerequisite (attendeeId from appointment details) and a rate limit, which is useful operational guidance. It does not explicitly name alternative tools or exclusions, but that is not a major gap given the tool's unique purpose.

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