Search mail

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

Annotations already provide readOnlyHint=true and openWorldHint=true, so the safety profile is known. The description adds some return-behavior context with 'compact summaries (no bodies)', but it does not disclose other behavioral details such as filtering semantics or result handling beyond what the schema already explains.

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 a single front-loaded sentence with no filler. 'Search the mailbox' states the action and resource immediately, and the parenthetical '(no bodies)' adds essential differentiation without extra words.

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 read-only search tool with a rich input schema, annotations, and an output schema, the description is sufficient: it tells the agent what the tool returns and what it deliberately omits. It does not explicitly route to sibling tools, but that gap is minor given the clarity of the schema and the tool's simple role.

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 all six parameters are already documented in the input schema. The description does not add parameter-level meaning beyond the 'summaries' framing, which is appropriate given that the schema carries the full semantic weight.

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 ('Search'), names the resource ('the mailbox'), and states the output form ('compact summaries (no bodies)'). This clearly differentiates it from imap_read_message, which returns bodies, and from imap_list_mailboxes, which lists mailboxes.

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 usage for searching and explicitly excludes bodies, which suggests it is for summary-level discovery rather than full-content retrieval. However, it does not name alternatives or state when to prefer imap_read_message or imap_export_for_runtime, so the usage boundary is left to inference.

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