Search Outbound Messages

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

The description adds valuable behavioral context beyond the annotations: 'paginated; up to 10,000 results' discloses a result limit and pagination behavior. It does not describe sorting or default filter semantics, but the read-only/idempotent hints already cover safety, and this extra detail is meaningful.

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 wasted words. It efficiently conveys the core action, optionality, and a key behavioral constraint (pagination and limit).

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?

With an output schema, read-only/hints, and a clear purpose, the description covers the essential aspects for a search tool. The mention of pagination and the 10,000-result limit is crucial, though it doesn't address potential edge cases like sorting or default filter combinations, which are minor gaps given the schema coverage.

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 70%, leaving 3 parameters undocumented (tag, subject, messagestream). The description only says 'optional filters' and does not compensate for these gaps or add any per-parameter context, falling short of the baseline expected at this coverage level.

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 'Search outbound messages' with 'optional filters' and pagination, identifying the action and resource. It does not explicitly contrast with sibling search tools like search_message_opens or search_message_clicks, but the focus on 'outbound messages' provides reasonable differentiation.

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 the tool is used when searching outbound messages, with optional filters and pagination controlling result size. It offers clear context but does not explicitly mention when not to use it or point to alternatives, stopping short of a 5.

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