ffmpeg__generate_proxy

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

With no annotations present, the description carries the full burden of behavioral disclosure. It explicitly notes that the tool returns JSON in stdout with output_path and applied parameters, and it documents defaults and aspect-ratio auto-calculation. However, it does not mention file overwrite behavior, whether the source file is untouched, or potential error conditions, leaving some behavioral aspects undisclosed.

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 well-structured with an initial purpose sentence followed by a @remarks and @param block. It is slightly redundant because the first sentence and @remarks both describe proxy generation, but each parameter entry is concise and adds necessary value. The length is appropriate given the seven parameters.

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 tool with seven parameters, no output schema, and no annotations, the description covers all parameter semantics, defaults, and the output format. It lacks details on error handling, prerequisites like ffmpeg installation, and edge cases, but overall it provides sufficient information for an agent to select and invoke the tool correctly.

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 input schema has zero descriptions (0% coverage), so the description must compensate. It provides detailed @param documentation for all seven parameters, including defaults (width=1280, crf=28, pixel_format=yuv420p), meaning (CRF lower = better quality), and purpose (fps to unify mixed-fps footage). This fully compensates for the schema's lack of descriptions.

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 opens with a specific verb 'Transcode' and clearly identifies the resource: 'high-bitrate source footage to an edit-friendly H.264 proxy.' This clearly distinguishes the tool from sibling operations like generate_thumbnail or export_video. The @remarks reinforces the purpose by stating it generates a lower-bitrate proxy for editing.

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 the applicable use case: converting high-bitrate source footage into an edit-friendly proxy. It provides clear context for when to use the tool, though it does not explicitly mention alternatives or when not to use it. The mention of 'edit-friendly' and 'proxy' is enough for an agent to differentiate from final export or thumbnail generation.

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