files_types

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

There are no annotations, so the description carries the full burden of behavioral disclosure. It makes clear the tool is a read-only listing operation and specifies the categories of information returned. For a simple, non-mutating tool this is sufficiently transparent, though it could have explicitly stated it has no side effects.

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?

A single sentence that is concise, front-loaded with the main verb and resource, and includes the key detail about what the list covers. There is no filler or repetition of schema information.

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 parameterless informational tool with no output schema, the description is complete: it states the action, the subject, and the expected content categories. An agent has everything it needs to decide to call this tool and interpret the response.

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 tool has zero parameters, so there is no parameter semantics to clarify. The baseline of 4 applies, and the description enriches understanding by explaining what the returned list will contain. No additional parameter guidance is needed.

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 specific resource ('supported RAG upload file types'), and further clarifies the content as extensions, MIME types, and extract notes. This clearly distinguishes it from sibling tools like file_upload and files_list, which operate on actual files rather than type metadata.

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 usage context is implied rather than stated: an agent would naturally call this before doing a RAG file upload to check supported types. However, there is no explicit guidance about when to use this tool versus alternatives, nor any statement of when not to use it. The description is adequate but leaves the selection logic to inference.

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