scan_by_ext

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It only states the scanning criterion and default extensions; it does not mention recursion, read-only behavior, symbolic link handling, or what the scan actually returns. For an agent, this is a notable gap in understanding side effects and scope.

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. It immediately conveys the action and scope, so it earns full marks for conciseness.

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 only 2 parameters, 100% schema coverage, and an output schema present, the description plus schema covers the fundamental inputs and defaults. Still, the lack of behavioral context (e.g., recursion, non-modification) and alternative routing leaves some ambiguity for an agent deciding whether this tool fits.

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%: both dirs and exts have explicit descriptions, and exts includes the same default list. The tool description adds no new semantic meaning beyond the schema; it essentially restates the default extensions.

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 a specific verb and resource: '按文件后缀扫描' (scan by file extension) and lists the default junk extensions. It is unambiguous in its main function, though it does not explicitly mention sibling tools to distinguish itself from scan_large, scan_duplicates, scan_old, or summarize.

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 default suffix list (.tmp/.log/.cache/.bak/.old) implies a cleanup/junk-file use case, which provides some contextual guidance. However, the description gives no explicit direction on when to prefer this tool over alternatives like scan_large or scan_old, and no exclusion criteria are stated.

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