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

With no annotations, the description fully carries the behavioral-disclosure burden, and it does so well: 'Returns metadata only. This tool never reads file contents.' It also discloses an important edge case: protected files are flagged with an asterisk and must never be suggested for deletion or moving. That is exactly the kind of behavior an agent needs to know.

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 information-dense without being bloated. Every block served a clear purpose: what the tool does, when to use it, row format, protected-file caveat, safety guarantee, and parameter meanings. The transition to parameters is efficient and the usage guidance is front-loaded.

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?

The tool's output schema relieves it from covering the return shape, and the description covers the workflow context, row layout, and protected-file handling. The main completeness gap is the undocumented 'max_depth' parameter, which could affect the scope of a listing and deserves clarification.

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?

While schema description coverage is 0%, the description adds substantial semantics for most parameters: defaults, unit semantics for 'not_opened_days' and 'min_size_mb', allowed categories for 'file_type', and the cap at 100 for 'limit'. However, 'max_depth' appears in the schema but is not described at all, so the compensation is incomplete.

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 uses a specific verb ('List') and a clear resource ('individual files in a folder'), then enumerates the four filters: age, size, type, and subfolder. It distinguishes itself from scan_folder by positioning itself as the drill-down step 'to see the actual files behind a summary line'.

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 explicitly tells the agent when to use this tool: 'Use after scan_folder to see the actual files behind a summary line.' It even gives concrete examples, such as 'the ones not opened in over a year, or the largest videos,' which makes the selection condition unambiguous relative to its sibling.

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

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.