set_blend_mode

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

Annotations are all false, placing full burden on description. The description discloses that the tool performs a write operation ('Set'), and adds context about the Opacity effect. However, it does not clarify whether the Opacity effect must already exist or if it is created automatically, nor does it mention undo behavior or side effects.

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?

Two sentences with no wasted words. The first sentence front-loads the verb and resource, and the second provides necessary context. Perfectly concise.

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 simple setter tool with no output schema and empty annotations, the description adequately states purpose and effect property. However, it lacks information about whether the Opacity effect is required or automatically added, and does not address error conditions. A brief note on effect existence would improve completeness.

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 descriptive parameter names and descriptions. The description adds extra context by linking the blend mode to the Opacity effect's property, providing meaning beyond the schema. This additional information justifies a score above baseline 3.

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 verb 'Set' and resource 'blend mode on a video clip', and further specifies it uses the Opacity effect's Blend Mode property, distinguishing it from sibling tools like set_clip_opacity. It is specific and unambiguous.

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 the tool is used to set a blend mode, and mentions the underlying effect property, but does not provide explicit guidance on when to use it versus alternatives. No exclusions or context on prerequisites are given.

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