anim_scale_keys

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

Annotations already mark the tool as destructive, so the description doesn't need to restate that. It adds useful behavioral context: all key times are multiplied, factor<1 speeds up, factor>1 slows down, and pivotFrame serves as the anchor. This makes the mutation concrete beyond the annotations.

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 compact and front-loaded, with the action and key semantics in the first sentence. Bilingual duplication is acceptable for accessibility and doesn't add material bulk or irrelevant detail.

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 definition covers the operation, the factor behavior, and the pivot anchor, while the input schema fully documents all parameters. For a mutation tool without an output schema, this is sufficient for an agent to call it correctly. The only missing piece is explicit guidance on choosing among sibling animation-timing tools.

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 100%, so the baseline is 3. The description adds relational meaning beyond the schema by explaining that factor scales time and that pivotFrame acts as the anchor point. It could clarify the exact formula when pivotFrame is nonzero, but the core semantics are clear.

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: 'time-stretch a whole track', with a precise mathematical definition (every key time multiplied by factor around pivotFrame). This clearly distinguishes it from sibling animation-timing tools like anim_offset_keys (shifting) and anim_set_keys (setting key values).

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?

Usage is implied by the description: use this when you want to speed up or slow down an entire track's key times around an anchor. However, there is no explicit guidance about when not to use it or which sibling tool to prefer for shifting vs. scaling keys.

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