ffmpeg__export_video

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

With no annotations, the description carries the full behavioral burden. It discloses supported codecs, the crf/bitrate interaction, and the JSON stdout return format with output_path and applied parameters. It does not mention overwrite behavior or failure modes, but the provided details go beyond the basic name/schema and give the agent actionable expectations.

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 long due to param listings, but each line adds necessary information because the schema provides no descriptions. The opening sentence front-loads the core purpose, and the @param lines are structured and scannable. No unnecessary filler, though it could be slightly more compact.

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 12-parameter tool with no output schema and no annotations, the description covers a lot: all parameter semantics, defaults, return format, and mode selection. Missing details like overwrite behavior and error reporting prevent a 5, but the description is sufficiently complete for an agent to invoke the tool correctly in most cases.

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 0%, but the description includes a @param entry for every one of the 12 parameters, adding defaults, examples, and mutual exclusivity. For instance, crf defaults vary by codec, bitrate overrides crf, and resolution keeps original if omitted. This fully compensates for the empty schema and exceeds the baseline.

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 and resource: 'Transcode a video to a delivery-grade output with full codec and quality control.' This clearly differentiates it from ffmpeg siblings like generate_proxy or generate_thumbnail, which serve different purposes. The scope (codec, quality control, delivery) is explicit and unambiguous.

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 clearly explains parameter usage: use crf for quality-based encoding or bitrate for target-bitrate mode, notes that bitrate takes precedence, and provides sensible defaults for codec, crf, preset, etc. However, it does not explicitly mention when to prefer this tool over alternatives like generate_proxy, so it lacks explicit exclusions but still gives clear context.

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