Set Keyframes

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

Goes well beyond the annotations: it discloses exactly what destruction occurs ('replaced: old keys removed') versus what is preserved ('merge: keep keys at other times'), states the precondition 'Fails if another expression is active', and describes the return value ('Returns the keys as set'). The shape-morph constraint (keep vertex count consistent across keys) is operationally important behavior an agent could not infer from the schema.

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?

Dense but front-loaded: the replacement semantics come first, then property-type caveats, then the failure condition, then the return value. Every clause carries information, though the shape-spec sentence is crammed into the middle without visual separation and the abbreviation 'as v' assumes schema familiarity.

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 destructive, 4-parameter mutation with no output schema and no schema descriptions, the description covers mode semantics, destruction scope, a failure precondition, and the return value. The remaining gap is parameter addressing (layer_id and the path identifier format), which an agent needs in order to actually invoke it.

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 carry the load. It explains the merge flag's semantics, what v means for path properties, and the spring/bounce interp values — but it says nothing about layer_id, the path parameter's string-vs-array addressing form, or the meaning of t. Partial compensation only.

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 specific verb and resource ('Replace all keys on a property') and immediately clarifies the two write modes (merge vs. replaced). It is clearly distinct from get_keyframes, but it never names or contrasts with the obvious sibling edit_keyframes, so the agent must infer the 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?

The merge/replaced parenthetical gives real guidance on mode selection, and 'interp spring/bounce ... works on any property' scopes a feature. However, there is no explicit when-to-use versus edit_keyframes, no mention of prerequisites such as locking or selection, and the failure condition is stated only incidentally.

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