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

The annotations already signal read-only behavior, and the description adds meaningful conditional behavior: no argument returns all input formats, while input_format narrows results to valid conversions. This is valuable context beyond the schema and annotations.

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 concise sentences with no filler. The primary purpose is front-loaded, and the conditional behavior is stated efficiently without redundant detail.

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 simple, optional-parameter, read-only listing tool with no output schema, the description covers the behavior an agent needs to call it correctly. Nothing important is missing.

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 coverage is 100%, so the schema already documents the parameter. The description adds semantic meaning by explaining the effect of omitting versus providing input_format, which goes beyond a simple type/description.

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 tool lists supported conversion formats and immediately distinguishes the two result modes based on the optional argument. This is specific enough to separate it from siblings like convert and list_options.

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 gives explicit guidance on when to omit or provide input_format, which is the main choice an agent faces. It does not explicitly contrast against sibling alternatives, but the behavioral distinction is clear and sufficient for this simple tool.

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