list_formats

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. The verb 'list' implies a read-only, non-destructive operation, which is useful. However, it doesn't disclose whether a network request is made, what the output format looks like (e.g., array of format objects, metadata fields), or potential error conditions (invalid URL, unsupported site). This is adequate for a simple read tool but not rich.

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, clear sentence with no wasted words. It front-loads the key action ('List') and immediately names the target resource. For a tool with one parameter and a straightforward purpose, this is appropriately concise.

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?

The tool has a single parameter and a simple purpose, so the description is largely sufficient to invoke it correctly. However, with no output schema and no mention of what 'formats' means or the return structure (e.g., a list of format objects with resolution, codec, etc.), an agent may be uncertain what to expect. Since annotations are absent and the description doesn't compensate for the missing output schema, it leaves a small but real gap.

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 description coverage is 100%, with the 'url' parameter already described as 'The URL to list formats for'. The description adds no additional meaning beyond calling it a 'video URL', which is essentially the same. Since the schema fully documents the parameter, the baseline of 3 is appropriate; the description does not compensate or expand on any parameter behavior.

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 ('all available formats for a video URL'). This clearly distinguishes it from siblings like download_video or download_stream, which perform downloads, and from get_video_info, which likely returns different metadata. An agent can easily tell what this tool does and when it's the right one.

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 gives no guidance on when to use this tool versus alternatives. It doesn't mention typical workflows (e.g., listing formats before choosing a download stream), nor does it advise against using it in certain situations. With multiple sibling tools available, the absence of any contextual routing leaves the agent to infer usage on its own.

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