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

Annotations declare readOnlyHint=false and idempotentHint=false, implying a non-idempotent mutation, but the description does not explain that this is likely an asynchronous job (callback_id suggests webhooks) or how results are retrieved. It adds no behavioral context beyond the terse annotations, leaving the async/submission semantics entirely 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?

Two words is technically brief, but this is under-specification rather than conciseness — there is nothing front-loaded because there is nothing to front-load. No sentence earns its place because no informative sentence exists.

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?

A 7-parameter, non-read-only tool with no output schema, no enums, and near-zero schema coverage needs the description to carry the burden; instead it says only "video subtitles". Nothing about required inputs, output retrieval, or async behavior is conveyed.

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 only 14%: just callback_id is documented (as a custom tracking ID). The description supplies no meaning for video_url, style_type, source_language, subtitle_format, or translate_language, so an agent must guess at formats, allowed values, and whether all are optional.

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?

"视频字幕" merely restates the tool name; the schema description "视频字幕任务。" adds nothing further. There is no verb (e.g. generate/burn-in/translate subtitles) and no differentiation from siblings like video_translate, video_analyze, or video_generate.

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?

No when-to-use guidance, no prerequisites, and no mention of alternatives such as video_translate despite subtitling and translation being closely related operations. The agent gets no basis for choosing this tool over its siblings.

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