Mark an email sent

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

Annotations are all false (readOnlyHint, etc.), so the description carries the burden of behavioral disclosure. It adds 'Does not actually send — tracking only,' clarifying the tool's non-destructive, non-sending nature. However, it does not detail side effects or permissions needed.

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, front-loaded sentences with zero wasted words. Every sentence adds value: the first states the action and effect, the second clarifies a key limitation.

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 simplicity (2 required params, no output schema, no nested objects), the description covers the core function and limitation. However, the complete lack of parameter documentation leaves a gap. It is minimally adequate but not comprehensive.

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 input schema has 2 parameters (id, project) with no description coverage (0%). The tool description provides no explanation of what id or project represent, leaving the agent to infer meaning solely from the tool name and context.

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 the action ('Record that a draft was sent'), specifies the resource (draft email), and differentiates from actual sending by noting 'Does not actually send — tracking only.' This distinguishes it from sibling tools like draft_email and list_mail.

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 (after a draft is sent, to record the event) and what it does not do (does not send), but does not explicitly state when not to use or name alternative tools. Guidance is implied rather than explicit.

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