video_add_text

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

With no annotations provided, the description carries full burden. It describes the core behavior (overlaying text) and mentions auto-generation of output path, but lacks details on permissions, rate limits, file format support, error conditions, or whether the operation is destructive to the original video.

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 efficiently structured with a clear purpose statement followed by well-organized parameter explanations. Every sentence adds value, with no redundant information. The parameter list uses consistent formatting and avoids unnecessary elaboration.

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 the tool's moderate complexity (10 parameters, video processing operation) and the presence of an output schema (which handles return values), the description is reasonably complete. It covers all parameters thoroughly and states the core behavior, though could benefit from more behavioral context about the operation's characteristics.

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?

With 0% schema description coverage, the description fully compensates by providing clear explanations for all 10 parameters. Each parameter's purpose is explained (e.g., 'Absolute path to the input video', 'Text to overlay', 'Position on screen' with specific options, 'Path to font file', etc.), adding significant value beyond the bare schema.

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 clearly states the tool's purpose with a specific verb ('Overlay') and resource ('text on a video'), and distinguishes it from siblings by specifying it's for text overlays (titles, captions, watermarks) rather than other video operations like cropping, merging, or adding audio.

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 usage through examples (titles, captions, watermarks) but doesn't explicitly state when to use this tool versus alternatives like video_subtitles or video_watermark. No guidance on prerequisites or exclusions is provided.

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