search_messages

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

With no annotations, the description carries the full disclosure burden and covers the key behavioral constraints: Security/OTP subjects are redacted, bodies are never returned, and email content is untrusted. It doesn't mention pagination, sorting, or exact metadata fields, but the disclosed constraints are non-obvious and valuable.

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 two short sentences with the core scope front-loaded: 'Search one folder.' Every clause adds distinct information—folder scope, metadata-only results, redaction, and content safety—with no fluff or repetition.

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 tool with no annotations, no output schema, and nine optional parameters, the description covers the crucial result constraints but leaves gaps: exact envelope fields, search-criteria combination semantics, and how to choose between this and sibling message tools. It is adequate but not fully self-sufficient.

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 description adds no parameter-level meaning beyond what the schema already provides. Parameters like to, unseen, and subject lack schema descriptions, and the description doesn't clarify their matching behavior or how criteria combine. With 67% schema coverage, some compensation was expected, but none is present.

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 states a specific verb and resource: 'Search one folder.' It immediately differentiates from get_message by saying 'Returns envelope metadata only' and 'bodies are never returned,' making the tool's role unmistakable among the sibling email tools.

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 provides clear context: use this for folder-scoped searches with metadata-only results, and it explicitly warns that bodies are never returned. It doesn't name an alternative tool outright, but the exclusion boundary is evident enough for an agent to avoid using it for message content retrieval.

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