file_stat

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

With no annotations, the description carries the burden of disclosing behavior. It accurately conveys a read-only operation and enumerates the returned metadata categories, but it does not mention behavior on missing paths, symlinks, or directory targets beyond the schema note.

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?

A single front-loaded sentence with no filler. Every word contributes to identifying the operation and output categories.

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 one-parameter read-only tool with no output schema, the description covers the essential invocation context and expected output categories. It could add return structure or error behavior, but these are minor for a simple stat operation.

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% and the single path parameter is already well documented as 'Target file or directory path.' The description adds no parameter semantics; it actually narrows the target to 'a file path,' which is slightly inconsistent with the schema's broader directory support.

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 ('Get') and resource ('stat metadata, permissions, size, and timestamps'), making it clear the tool returns filesystem metadata rather than file content or listings. This distinguishes it from sibling tools like file_read and file_list.

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 gives no indication of when to use file_stat versus related sibling tools, nor does it mention any exclusions or alternative tools. An agent must infer applicability solely from the tool name and listed output fields.

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