files

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

With no annotations, the description is the sole source of behavioral information. It states only that the tool returns file paths, but does not disclose potential side effects, permission requirements, error behavior, or whether the operation is read-only. This lack of transparency could lead to unexpected outcomes.

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, concise sentence that directly conveys the core function. It is well-structured and free of unnecessary detail, making it easy to parse.

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 the tool's simplicity, the description covers the basic purpose but lacks essential contextual information. It does not explain parameter semantics, return format, or how this tool relates to siblings like 'search' or 'ids'. This incompleteness hampers correct usage.

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 schema provides no descriptions for the three parameters, and the tool description does not explain them either. 'query' is mentioned but its format and syntax are undefined; 'account' and 'include_excluded' are completely unexplained. This leaves the agent unable to construct correct invocations.

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 action ('Return') and the object ('maildir file paths'), and specifies that results are based on a query. However, it does not elaborate on what constitutes a 'matching' query, leaving some ambiguity about the exact filtering criteria.

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 no guidance on when to use this tool versus its siblings (e.g., 'search', 'ids', 'show'). There is no mention of use cases, prerequisites, or scenarios where this tool is preferred, leaving the agent without direction on tool selection.

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