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

With no annotations provided, the description carries the behavioral disclosure burden. It does well by explaining exactly what each mode does and disclosing the no-op condition for tracks with fewer than 2 keyframes. It does not mention overwriting behavior or return output, but for a simple setter the mode semantics and edge-case caveat provide meaningful transparency.

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 three sentences with no filler. The primary action is front-loaded, the detailed mode definitions are necessary for correct invocation, and the short keyframe-count caveat is valuable. Every sentence earns its place.

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 four required parameters, no annotations, and no output schema, the description covers the key operational facts: what the tool sets, what each mode means, and when it does nothing. It is slightly incomplete only in not explicitly routing the agent away from the similarly named sibling set_loop.

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 50%, with elementId and projectId already explained. The description compensates for the mode parameter by thoroughly defining hold, loop, ping-pong, and cycle. It does not add much about the property enum, but those values are self-explanatory, and the phrase "one property's animation track" clarifies the role of property.

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 opens with a specific verb and resource: "Set the extrapolation mode for one property's animation track." It is clearly scoped to a per-property track, which helps distinguish it from the sibling set_loop, though it never names set_loop explicitly. The four mode values are explained, adding precision to what the tool accomplishes.

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 for configuring extrapolation after keyframes and explicitly notes it has no effect on tracks with fewer than 2 keyframes. However, it does not mention the sibling tool set_loop or any explicit condition for choosing this tool over alternatives. Usage context is present but alternate routing is left to inference.

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