set_blend_mode

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

No annotations are provided, so the description must fully disclose behavior. It only mentions the internal mechanism but omits critical details such as whether the effect is automatically added if missing, error handling for non-video clips, or side effects (e.g., overriding previous blend mode).

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 concise with two sentences, no redundant information. It front-loads the purpose. However, it could be improved by adding a brief usage note without becoming verbose.

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 lack of annotations and output schema, the description is too minimal. It does not explain return value, error conditions, or what happens if the clip is not a video. For a simple two-parameter tool, more context is needed for reliable invocation.

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 100% with clear parameter descriptions. The tool description adds no additional meaning or context beyond the schema. According to guidelines, when coverage is high, baseline is 3, and the description does not improve it.

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 action ('set the blend mode') and the resource ('video clip'), and mentions the specific mechanism ('Uses the Opacity effect's Blend Mode property'). This differentiates it from sibling tools like set_clip_opacity or set_frame_blend.

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 provides no guidance on when to use this tool versus alternatives like apply_effect or set_clip_opacity. It does not mention prerequisites (e.g., does the Opacity effect need to be applied first?) or scenarios where this tool should be avoided.

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