evaluate_curve_at_time

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

Annotations already declare readOnlyHint/idempotentHint/destructiveHint=false, so safety is covered. The description adds real behavioral context beyond that: it discloses that the asset is loaded from a path, that multi-channel curves have 3 or 4 components, and that the scalar 'value' reflects only the selected channel while 'values' always carries the full component array.

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?

Purpose is front-loaded in the first sentence, with channel semantics immediately after. The trailing Returns block is long but is the only place the output fields are documented, so each field earns its place.

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?

With no output schema, the description compensates by spelling out the returned fields (curve_class, curve_type, num_channels, value, values, vector, color), which is exactly what an agent needs. It stops short of covering failure modes (invalid path, unsupported curve class) or how curve_class is resolved.

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 goes further by explaining the coupling between 'channel' and 'value'/'values' for Vector and LinearColor curves, which clarifies the channel parameter's effect in a way the schema's one-line description does not.

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 ("Evaluate a curve asset at a given time") and enumerates the supported asset classes (UCurveFloat / UCurveVector / UCurveLinearColor), which is concrete and actionable. It does not, however, distinguish itself from sibling read tools such as get_curve_keys or get_anim_curve_data, so an 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?

Usage is implied by the purpose (evaluate a curve at time T), but there is no explicit when-to-use, when-not-to-use, or named alternative among the many curve-related siblings. A reader gets the context but no routing guidance.

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