video_subtitles_styled

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

With no annotations, the description carries the full disclosure burden. It does not say that burning subtitles is a permanent re-encode of the video, that the source must not already have burned-in captions, or how the overwrite flag behaves (that detail lives only in the schema). Only the return shape is mentioned.

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?

Front-loaded with the core action and structured with Args/Returns blocks. The second sentence ('Embeds subtitle file into video...') largely restates the first, and the Returns block duplicates the existing output schema, but overall it is tight.

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?

Output schema exists, so the Returns section is redundant rather than additive. For a lossy, irreversible mutation tool with zero annotations, the description should say more about overwrite semantics and that the original video is not modified, but is only marginally adequate.

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 coverage is 20%, so the description must compensate. It documents input_path, subtitles_path, output_path, and gives the style dict meaningful content ('font, size, color, outline, etc.'), which goes beyond the generic object schema. However, the overwrite parameter is never mentioned and the style key list ends in 'etc.', leaving real ambiguity.

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?

States a specific verb and resource ('burn subtitles from SRT/VTT with custom styling', 'embeds subtitle file into video'). This clearly separates it from plain subtitle handling, though it never names the obvious sibling video_subtitles or video_generate_subtitles to make the distinction explicit.

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?

There is no guidance on when to pick this over video_subtitles, video_generate_subtitles, video_translate_captions, or video_add_text. The reader can infer it is the 'styled/burned-in' variant, but nothing about prerequisites, irreversibility, or alternatives is stated.

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