calculate_file_stats

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

No annotations are provided, so the description must carry the full burden. It implies a read-only operation ('statistics') but does not explicitly state that it does not modify files. It also does not describe performance characteristics or side effects.

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 sentence, which is concise, but it is too vague to be effective. It lacks structure and does not front-load critical information. It could be expanded to include what stats are returned.

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 no output schema, the description should explain the return format or example output. It does not. The tool has three parameters with defaults, but the core functionality (what 'statistics' means) is undefined, making it incomplete for an agent to understand the tool's behavior.

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%, so the parameters are already documented with defaults and types. The description adds no additional meaning beyond the schema, which is acceptable but not helpful. The default values are clear from the schema.

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 states it calculates statistics for files in a directory, which is a specific verb+resource. However, it does not specify what statistics (e.g., count, sizes, permissions), making it somewhat vague. It is distinguishable from sibling tools like list_directory or search_files, but lacks specificity.

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?

No guidance on when to use this tool versus alternatives like list_directory or search_duplicates. No mention of when not to use it or prerequisites. The description leaves the agent without context for selection.

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