get_inbound_mail

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

Annotations already indicate read-only, idempotent, and non-destructive behavior. The description adds value by noting the default include parameter and warning that signed_urls should only be added when temporary file access is truly needed, providing guidance beyond annotations.

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 only two sentences, no wasted words. The first sentence gives the core purpose, and the second provides actionable usage context. It is front-loaded and efficient.

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 retrieval tool with an output schema (not shown), the description adequately covers the workflow role, default behavior, and a specific caution. It does not explain return values, which is acceptable given the output schema exists.

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 all parameters are described. The description adds meaningful context by explaining the default behavior of 'include' and cautioning about 'signed_urls'. This provides additional semantics beyond the schema descriptions.

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 tool retrieves a single inbound mail item with a default compact draft_context, and specifies it should be used before drafting an outbound reply. It effectively distinguishes from listing tools like list_inbound_mail by emphasizing the need for sender context and thread linkage.

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 explicitly tells when to use the tool ('before drafting an outbound reply') and lists the context it provides. It does not explicitly state when not to use it or mention alternatives, but the given sibling context includes list_inbound_mail, which partially addresses this.

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