Find duplicate files

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

With no annotations at all, the description carries the full behavioral burden and succeeds: it discloses the hash-based comparison method, that the scan is recursive, what it reports (file name, every location, count, wasted disk space), and the 20000-file truncation cap with the truncated:true flag. This is unusually thorough for behavior disclosure.

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 dense sentences with the core purpose front-loaded and supporting detail (output contents, truncation behavior) following. No wasted words, though the sentence is slightly long; still well within an appropriate size for the information conveyed.

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?

Despite having no output schema and no annotations, the description explains the return value shape (per-group file name, locations, count, wasted space) and the truncation edge case. The one friendly-name resolution behavior lives in the schema. For a single-parameter scanning tool, this is essentially complete.

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% — the path parameter already documents 'Folder to scan, or a friendly name like documents'. The description adds no additional parameter-level detail beyond what the schema provides, so the baseline of 3 applies.

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 a specific verb (recursively scan), a specific resource (folder for duplicate files), and the matching criterion ('same content, by hash - not just same name'). This clearly differentiates it from sibling tools like list_folder_contents, which would only enumerate files.

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 makes the tool's purpose evident (finding content-based duplicates) and explicitly rules out name-only matching, which helps an agent decide when it applies. However, it never names an alternative tool or states explicit when-not-to-use conditions, so usage guidance is implied rather than direct.

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