scan_folder

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

With no annotations present, the description carries full behavioral disclosure. It states the tool returns an aggregated rollup, remains cheap for large folders, skips specific folder types and reports how many were skipped, and counts protected files without exposing them as removable. This goes well beyond the input schema.

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 efficient, with the primary purpose captured in a single opening sentence, added guidance in short dense paragraphs, and parameter documentation at the end. Every sentence contributes a concrete behavioral or usage detail; there is no filler.

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 output schema exists and sibling list_files is named, the description provides all necessary context: when to invoke it, what to do after, what is excluded, how protected files are handled, and full parameter semantics. An agent has enough to select and invoke it correctly without further inference.

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 0%, so the description must compensate fully, and it does. It explains path with a realistic example and describes max_depth as 'how many levels of subfolder to descend' along with its default, which gives an agent actionable meaning beyond the bare schema types.

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?

Starts with a specific verb-resource pairing, 'Summarize a folder', and names what is summarized: what dominates, how old the contents are, and where data sits. It also distinguishes itself from the sibling list_files by stating it returns a rollup rather than a file list, so an agent can tell which tool fits.

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 is explicit: 'Call this first' and 'Follow with list_files' to inspect what the summary flags. It also gives rejection criteria — protected files should never be suggested for removal and certain folders are excluded — making usage boundaries and downstream actions clear.

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