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

With no annotations provided, the description carries the full behavioral burden and does so thoroughly. It discloses limits (100MiB/10min), accepted audio formats, that the private original is preserved, the returned MP3 URL/MIME/duration/poster_url behavior, visual media output retention, that no publication occurs, and the prerequisite that FFmpeg must already be installed.

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 dense but mostly front-loaded: purpose, limits, formats, outputs, exclusions, and prerequisite each earn their place. It is appropriately sized for the amount of behavioral detail required, though the run-on paragraph could benefit from clearer structural separation.

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?

Given no output schema and 0% parameter description coverage, the description does well by explaining return values, constraints, preservation behavior, and the FFmpeg prerequisite. It is only incomplete regarding the token and filename parameters, which are required but never described.

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% for all three required parameters. The description adds meaningful semantics for the media data (base64-supplied, format list, size/duration limits), but it does not explain the required token or filename parameters at all. This leaves two of three parameters undocumented in both schema and 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 opens with a specific verb and resource: preparing authorized base64-supplied visual or audio media using ffprobe/ffmpeg. It distinguishes the tool from sibling publishing and fetching operations by stating 'No arbitrary path/URL fetch, no publication.' An agent can identify its scope without opening the schema.

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 clear context and two exclusions ('No arbitrary path/URL fetch, no publication'), which helps rule out inappropriate uses. However, it does not name when to choose this tool over siblings like online_content_edit or online_article_publish, nor does it provide explicit routing alternatives. Usage is implied rather than fully guided.

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