Get Attachment Metadata

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

Adds value beyond readOnlyHint and other annotations by clarifying that the tool returns 'metadata only, not file bytes'. This tells the agent exactly what to expect and is consistent with the safe, idempotent nature.

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 sentences, front-loaded with actionable guidance. Every word serves a purpose; no redundancy.

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 excellent annotations, 100% schema coverage, and an output schema, the description is complete. It clearly states the tool's purpose, behavior, and usage context without needing to reiterate structural details.

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 100%, so baseline is 3. The description mentions 'temporary Sending attachment_id', which confirms the parameter's role but does not add new semantic detail beyond the schema's description.

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 uses a specific verb 'inspect' and resource 'temporary Sending attachment_id', clearly distinguishing it from sibling tools like mailbox_get_attachment and sending_send_email. It states the tool's role in the workflow ('before sending').

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 explicit context for when to use ('before sending'), but does not include exclusions or alternatives beyond what is implicit. The mention of 'not file bytes' helps avoid confusion with tools that return full content.

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