animation_setKeyframe

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

There are no annotations, so the description must disclose side effects or return behaviors. It only describes the input format (vec2 vs scalar) and does not mention overwriting existing keyframes, error conditions, or whether the tool mutates state persistently. This leaves the agent without information about potential consequences.

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, front-loaded with the main action, and contains no redundant information.

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 4-parameter tool with no output schema and no annotations, the description is somewhat minimal. It covers the critical value shape nuance but omits potential behavioral details like overwrite semantics or failure modes, making it adequate but not rich.

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 input schema covers all four parameters with 100% coverage. The description builds on this by explicitly listing which channel types (translation, scale) use vec2 values and which (rotation, opacity, shear) use scalar numbers, adding clarity beyond the schema's anyOf definition.

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 starts with 'Set a keyframe value on an animation channel,' clearly stating the verb and resource. It distinguishes from sibling tools like animation_getKeyframes, animation_deleteKeyframe, and animation_setInterpolation by specifying the setting action.

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 clear context for when to use the tool: whenever you need to set a keyframe value. It also gives channel-specific value format guidance, which helps the agent avoid errors. However, it does not explicitly mention alternatives or prerequisites, so it stops short of a 5.

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