motion_add_keyframe

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

With no annotations, the description carries the burden of disclosing behavior. It clearly indicates the append operation and the existing-curve prerequisite, but does not describe potential errors when the precondition is violated, nor the effect of the optional interpolation parameter. It provides some useful context but lacks full behavioral disclosure for a mutating tool.

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 primary action, and uses the second sentence to provide a critical workflow alternative. Every word earns its place; no redundancy or filler.

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 description effectively captures the tool's core purpose and its relationship to a sibling tool, which is especially important given no annotations. However, it omits important operational details like parameter format/encoding, interpolation behavior, and failure modes. Given the tool's moderate complexity and six parameters, this is only partially 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 compensate for parameter meaning. It does not explain any of the six parameters individually, such as the format of 'path', 'parameter_path', 'value', or how 'interpolation' affects the keypoint. While the names and context hint at semantics, the description adds no concrete parameter-level guidance.

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 ('Append a keypoint') and identifies the resource ('a parameter that is ALREADY keyframed in Motion'), clearly differentiating from the sibling tool motion_create_keyframe_curve. It also specifies the precondition of an existing curve, making the tool's purpose unmistakable.

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 explicitly states when to use the tool (append to an already-keyframed parameter) and when not to use it (if never keyframed), directing the agent to call motion_create_keyframe_curve first. This is exemplary guidance for tool selection.

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