setup_video_reference

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 discloses that the tool modifies the compositor (attaches video) and explains the video_frame_offset behavior, which is useful. However, it does not mention side effects such as overwriting existing references, whether the operation is reversible, or any prerequisite like video_path validity. This is a partial disclosure for a state-changing tool.

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 two sentences with no filler. It front-loads the primary purpose and then adds a param-specific detail. Every clause earns its place, and the structure is efficient.

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?

For a tool with 3 parameters and an output schema, the description gives enough to call correctly: it states the action, the effect, and the timing offset. It does not mention any return value, but that is covered by the output schema. The main gap is lack of guidance on when to use this vs sibling overlays, but that is more of a usage guideline issue. Overall, an agent can safely invoke it without missing critical context.

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%, so the description must compensate. It explicitly explains video_frame_offset's effect and implies model_opacity's role via the rendering statement. video_path is self-explanatory by name. While not exhaustive, the description provides meaningful context beyond the schema for two parameters, leaving video_path clear enough.

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 states a specific verb ('attach'), a resource ('reference video to Blender's compositor'), and a clear purpose ('pose-by-pose rotoscoping'). It distinguishes from siblings like inspect_video_overlay and render_video_overlay by focusing on setup rather than inspection or rendering.

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 (necessary for rotoscoping) but does not explicitly state when to use this tool vs alternatives or mention any exclusions. There is no mention of when a different tool like inspect_video_overlay would be more appropriate, leaving the agent to infer from the purpose.

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