set_anim_curve_comment

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

Annotations already flag destructive=true, idempotent=true, readOnly=false. The description goes well beyond them: one undo step, a package save that is metadata-only and does not affect evaluation, exactly what is written when the curve name is invalid (nothing), idempotent success with applied=false and saved=false, and save-failure semantics (success=false, saved=false, save_error). That is substantial behavioral context beyond the structured fields.

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 leading sentence front-loads the core action and scope, and the subsequent sentences each carry distinct rules (type restriction, no-op case, save-failure case). It is dense but every clause earns its place; slightly run-on but not padded.

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?

There is no output schema, so the description correctly supplies the return shape ({anim_sequence_path, curve_name, comment, applied, saved, save_error, message}). Combined with the error and no-op cases, an agent has everything needed to call this correctly and interpret the result.

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 real semantics on top: curve_name must be a float curve of the sequence (transform curves rejected), the comment comparison is case-sensitive, and comment defaults to empty. These clarify the two required params beyond their schema blurbs.

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 verb and resource ('Set the author comment of a FLOAT curve on a UAnimSequence'), plus the mechanism ('through its data controller'). This distinguishes it cleanly from siblings such as set_anim_curve_color, set_anim_curve_interp_mode, and set_anim_curve_keys without needing to open any schema.

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?

It gives clear applicability constraints: FLOAT-CURVE ONLY, transform curves are an error, and the no-op case when the comment already matches. It stops short of explicitly naming an alternative sibling for transform curves, so the 'use X instead' routing is left implicit rather than stated.

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