keyframe_shape_key

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

With no annotations, the description must carry behavioral context. It does disclose the key action, the special 'omit value to key current value' behavior, and the return shape, but it omits important details such as whether existing keyframes are overwritten, whether animation data is created, or what prerequisites 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?

The description is front-loaded with the core action in one sentence, followed by clear Args and Returns sections. It is efficient with little wasted text, though the parameter descriptions could be slightly more precise.

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 output schema exists, so the return value need not be fully explained, and the description does briefly cover it. However, for a mutation tool with no annotations, the description lacks enough behavioral context about side effects, overwrite behavior, and prerequisites to be fully complete.

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 document all four parameters. It does so for object_name, key_name, frame, and especially value, explaining that omitting value keys the current value; the meanings are brief but sufficient for correct invocation.

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 uses a specific verb and resource: keyframing a shape key's value for blend-shape animation. It is clearly distinct from generic mesh editing tools, though it does not explicitly differentiate itself from siblings like insert_keyframe or keyframe_property.

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 phrase 'so the blend shape animates' implies the intended use case, but there is no explicit guidance on when to choose this tool over insert_keyframe, keyframe_property, or set_shape_key. No exclusions or alternatives are named.

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