add_keyframe

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

With no annotations, the description carries the full burden for a mutation tool. "Add/update" weakly implies an existing keyframe at the same time is overwritten, but it never confirms overwrite vs duplicate behavior, says nothing about required effect/property state, undo, or whether prior keyframes on that property are preserved. The "must be inside the clip" constraint is the one real behavioral fact offered.

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 short sentences, no filler, and the operation is front-loaded before the time constraint. Nothing in it is wasted, even if more could usefully have been added.

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 an 8-parameter, 7-required mutation tool with no annotations and no output schema, the description is thin. It omits what is returned, the default/explicit interpolation behavior, how effect/property resolution works, and what happens to conflicting keyframes, leaving the agent to infer invocation details from the schema alone.

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 75%, so most parameters are already documented, but the description adds genuinely non-derivable semantics for `time`: it is sequence time in seconds, not clip-relative time, and must fall inside the clip bounds. That resolves an ambiguity the schema ("number, minimum 0") leaves open.

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?

States a concrete verb+resource ("Add/update a keyframe"), which is better than a tautology, but never says what the keyframe is attached to (an effect property on a clip) or how it differs from siblings like set_effect_property, get_keyframes, or set_keyframe_interpolation. An agent can guess the domain but not the exact operation boundary.

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?

No when-to-use guidance at all: nothing about how this relates to set_effect_property (static value) or when to use get_keyframes first to resolve names/indices. The only guidance given is a constraint on the time value, not on tool selection.

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