list_backends

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

No annotations are provided, so the description carries the full burden. It states what the tool does but does not explicitly mention that it is read-only or side-effect-free. However, as a listing operation, this is largely implicit. It also does not describe the output structure, but the existence of an output schema mitigates that. The description is adequate but lacks explicit behavioral detail.

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 a single, well-formed sentence that contains no filler or redundant words. 'List registered format backends and their file extensions' is succinct and front-loads the core function. There is zero waste.

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 zero parameters and the presence of an output schema, the description is sufficient for an agent to understand the tool's purpose and invoke it correctly. It specifies the output informally and the output schema can handle formal structure. No additional context about errors or ordering is needed for a simple list operation.

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 per the rubric the baseline is 4. The empty input schema and 100% schema description coverage mean there is nothing to explain. The description accurately reflects that no arguments are needed, and the tool's purpose is fully self-contained.

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 clearly states the action ('List') and the resource ('registered format backends') and specifies what is included ('their file extensions'). It is unambiguous and distinct from the sibling tools, which focus on document operations or export. The verb and object are specific, meeting the highest bar.

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 provides no guidance on when to use this tool versus alternatives. It does not mention any context, prerequisites, or relationships to sibling tools like export_document. An agent would have to infer that this might be useful before exporting, but the description says nothing.

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