list_directory

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

Annotations already declare read-only and non-destructive behavior. The description adds a valuable permission requirement ('Requires allow_file_read in ~/.syscontrol/config.json') and lists the exact return fields, providing context beyond the 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 three sentences long and front-loaded with the primary action. It includes essential return fields, use case, and permission requirement without any redundant or irrelevant information.

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 simple tool with no required parameters and no output schema, the description covers return fields, permission needs, and a use case. It does not explicitly state that listing is non-recursive, which could be ambiguous, but sibling tools like search_files cover recursive cases, making this acceptable.

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 input schema has 100% coverage with clear descriptions for both parameters (path defaults to home directory, show_hidden includes dotfiles). The description does not add parameter-specific detail, but the schema already handles it, so the baseline score of 3 is appropriate.

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's verb and resource ('List the contents of a directory') and specifies the returned fields. It is easily distinguished from sibling tools like read_file or search_files by its focus on directory browsing.

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?

Provides explicit context: 'Use to browse the filesystem or verify file presence.' However, it does not mention when to use an alternative tool (e.g., search_files for recursive searches) or any exclusions, so it lacks full alternative guidance.

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