summarize_directory

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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint false. The description adds value by specifying the exact output shape (per-subdirectory sizes, file counts, top-N list) and the permission requirement 'allow_file_read', which goes beyond the structured 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?

Two concise sentences front-load the core functionality, add a practical benefit, and note a prerequisite. Every sentence earns its place with no redundancy.

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 read-only tool with strong annotations, the description sufficiently covers purpose, output, and permissions. It lacks details on return format specifics or error handling, but the annotation safety profile and output description are enough for a typical agent to correctly invoke it.

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?

With 0% schema description coverage, the description must clarify parameters. It explains 'configurable depth' for the depth parameter and 'top-N list' for top_n, but does not explicitly address the path parameter beyond the implied directory tree context. This partial compensation is adequate but not complete.

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 walks a directory tree and returns summary statistics (sizes, file counts, largest subdirs). It distinguishes itself from sibling list_directory by explicitly noting it saves many such calls.

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 phrase 'Saves many list_directory calls' implies when to use this tool over alternatives, providing clear context for its intended use case. However, it does not explicitly name alternatives or state when not to use it beyond that implication.

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