list_codecs

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

No annotations are provided, so the description carries the behavioral burden. The word "List" implies a read-only enumeration and there are no parameters or side effects to disclose, but the description does not explicitly state that it is non-mutating or describe any runtime constraints.

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 efficient sentence that front-loads the action (list), the resource (codecs and image formats), and the useful extra detail (quality defaults). There is no filler.

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 zero-parameter listing tool with an output schema, the description is nearly complete: it says what will be listed and that quality defaults are included. It could be slightly stronger by clarifying that it is a static/read-only catalog, but the output schema removes the need to explain return structure.

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 takes zero parameters, so there are no parameter semantics to explain. The baseline for zero-parameter tools is 4, and nothing in the description creates ambiguity about inputs.

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 and resource: it lists supported video/audio codecs and image formats, plus their quality defaults. That clearly distinguishes it from sibling tools like probe_media or transcode_video, which inspect or process media rather than enumerate supported formats.

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 implies this is a discovery/reference tool, but it does not explicitly say when to use it versus alternatives such as probe_media. There are no exclusions or stated prerequisites, so the agent can infer usage but must do so from context.

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