list_files

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

With no annotations, the description carries the burden of behavioral disclosure. It adds value by explaining that 'sources' contains ingested items like web pages/clipboard, and that files are scanned from base directories. It doesn't explicitly state this is read-only or describe side effects, but the 'list' verb implies safety. Some edge behavior (e.g., invalid scope yielding empty files list) is only visible in the schema, not the description.

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 two concise sentences: the first states the core purpose, and the second explains the return structure and the 'sources' nuance. There is no redundancy or filler, and the most important information 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?

For a listing tool with one optional parameter and no output schema, the description sufficiently covers the purpose, return shape, and the non-obvious 'sources' concept. It doesn't need to explain return values in detail since the return shape is stated. Path edge cases are handled in the schema, so the description is complete enough for correct selection and invocation.

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?

The schema description covers 100% of the parameter 'scope' with a detailed explanation of prefix matching and path constraints. The tool description adds no additional parameter semantics beyond what the schema already provides, so the baseline 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 ('list') and resource ('supported files (PDF, DOCX, TXT, MD)') under configured base directories, plus the ingestion status. This clearly distinguishes it from sibling tools like ingest_file, delete_file, and sync_status, which perform different operations.

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 clearly implies the tool is for inspecting the file inventory and its ingestion status, which is a distinct use case. It also explains the return shape to set expectations. However, it doesn't explicitly mention when not to use it or reference sibling alternatives, though the purpose is clear enough for selection.

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