get_file_info

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

Annotations already declare readOnlyHint=true, so the safety profile is covered. The description adds that it returns specific metadata fields and warns about large files, but it doesn't discuss error handling, path existence, or directory-specific behavior. This is modest added context, appropriate given the low bar set by annotations.

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 sentences, front-loaded with the primary function and metadata types. It includes a practical usage hint and parameter mention without any waste, achieving maximum 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?

Given the tool's simplicity (one parameter, read-only, output schema present), the description covers the main metadata returned and a key use case. It doesn't elaborate on edge cases, but the output schema and annotations fill some gaps, making it fairly complete for the tool's complexity.

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 only provides a required string 'path' with no semantic detail, and the description merely repeats 'path (required)' without explaining accepted formats, relative vs absolute paths, or how directories versus files are handled. With 0% schema coverage, the description fails to compensate sufficiently.

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 tool retrieves file/directory metadata (size, timestamps, permissions, type), which is a specific verb plus resource. It distinguishes itself from content-reading tools like read_text_file by focusing on metadata rather than file contents.

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?

It gives an explicit use case: 'Use this to check file size before reading large files with read_text_file.' This names an alternative tool and specifies a scenario. It doesn't explicitly mention when not to use, but the guidance is clear and actionable.

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