overlay

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

No annotations are provided, so the description carries the full burden. It indicates the output is burned into a video and limits images to local raster files, but it does not disclose whether the input is preserved, whether existing output is overwritten, or what processing limitations or side effects exist.

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?

One compact sentence that front-loads the action and object, with no filler or redundant restatement. It is appropriately sized for the core purpose it conveys.

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?

The schema is complex with nested objects, a two-option overlay union, and time-based parameters, yet the description is a single clause. It omits return/result behavior, coordinate/unit context, and how the time window maps to start/end, so the agent cannot fully predict call behavior.

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?

The description adds some meaning by distinguishing typed text from raster image overlays and mentioning a time window, but it does not explain the required input, output, or frame parameters. With schema description coverage at 0%, this is only partial compensation for the missing parameter documentation.

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 names a concrete operation ('Burn'), a specific resource ('a video'), and the overlay content types ('typed text' or 'local raster image'), plus a time constraint. This clearly differentiates it from siblings like concat, trim, audio_mix, or health.

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 no guidance on when to use overlay versus alternatives such as transform or render, and no explicit when-not-to-use conditions. An agent must infer applicability solely from the operation name and the single sentence.

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