animate

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

With no annotations, the description carries the full burden. It does disclose one behavioral trait — that it returns a curve check for speed spikes and loop seams — which is genuinely useful since there is no output schema. However, it never states that this is a mutating operation, what happens to pre-existing keyframes/actions, or any permission/scope constraints, which is a significant gap for a 7-parameter authoring 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?

Two tight sentences, front-loaded on capability, with the return-value note appended. No filler, though the parenthetical list of easing libraries is somewhat brag-like rather than operational.

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?

Because there is no output schema, the description's one-line mention of the curve check is valuable and partially fills that gap. But for a 7-parameter, no-annotation mutation tool, the definition omits usage context, mutation semantics, and sibling differentiation, leaving it only minimally 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 86%, so the schema already documents bone, keys, loop, action, property, and relative including an inline ease example. The description adds no parameter meaning beyond this, so the baseline 3 is appropriate; it does not compensate for or extend the schema.

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 names a specific action (keyframing) with a distinctive attribute (per-segment designer-grade easing via Easy Ease, cubic-bezier, back/bounce/elastic) and previews a return artifact (curve check). That is enough for an agent to understand the tool builds animated keyframes, but it never distinguishes itself from the nearby siblings animate_preset, check_animation, or rig_character, which overlap in theme.

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?

There is no when-to-use or when-not-to-use guidance and no routing to alternatives. Given siblings like animate_preset (presumably canned animations) and check_animation, the description should say when to hand-author keyframes with this tool versus using a preset, but it offers nothing.

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