Read F-Curve

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It states the operation is non-mutating ('Does not create a track/curve or change document time'), adds a hard limit ('At most 1000 keys'), notes the snapshot semantics ('stable key indices for this snapshot'), and clarifies what it is not. This is strong coverage, though it could also mention error behavior when the track does not exist.

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 tight and dense: the first sentence states the core capability and data returned, the second adds the sampling option and the 1000-key limit, and the third clarifies side effects and exclusions. No sentence is redundant, and the most important scoping information is front-loaded.

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 tool has 7 parameters, no output schema, and no annotations, so the description must communicate both behavior and return content. It lists the returned data categories, the optional sampling behavior, the key limit, and side-effect guarantees. It is not fully complete because it does not describe response format, ordering, or failure modes, but it covers the essential calling context well.

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 100%, so the schema already documents every parameter, including exclusions between path/param_id/component and the semantics of sample_frames. The description adds the optional sampling concept and the key limit, but does not substantially expand parameter meaning beyond what the schema provides. Baseline 3 is appropriate.

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 uses a specific verb ('Read') and resource ('existing REAL F-Curve'), and enumerates exactly what is returned: key indices, frame times, values, interpolation, tangent offsets, and extrapolation. It also distances itself from other readers ('Not a scene/constraint evaluation or character-animation reader'), making its purpose unmistakable.

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 description makes clear this is for reading existing real F-curves only and explicitly states it does not create tracks or change document time. It also excludes scene/constraint evaluation and character-animation reading. It does not name sibling alternatives like get_keyframes or edit_fcurve_keys directly, but the exclusions give enough contextual guidance.

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