set_sub_section_parameters

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

Annotations already flag destructive=true and idempotent=true, so the safety profile is partly covered, but the description adds genuine behavioral detail: it writes the public FMovieSceneSectionParameters fields directly and that bCanLoop gates the loop offsets, so it must be applied first — an ordering constraint not present in annotations or schema. It stops short of saying whether changes are persisted or must be saved separately.

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?

Front-loads the core purpose and the key ordering rule in the first two sentences with no filler. The Returns block is lengthy but justified since there is no output schema to carry that information.

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?

For a 10-parameter mutation tool with no output schema and partial annotation coverage, the description covers the target types, the write semantics, the ordering constraint, and the full return shape (including saved/save_error). It is close to complete; only error/undo behavior and required prerequisites are unstated.

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, but the description earns above baseline by explaining cross-parameter semantics: bCanLoop acting as a gate for the loop offsets and the required ordering between can_loop and first_loop_start_frame_offset.

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 (Set) and resource (sub-section playback parameters) and explicitly disambiguates the two target types ('subsequence OR cinematic-shot section (both are UMovieSceneSubSection)'), which is a real distinction against the many section-oriented siblings like set_section_range or set_skeletal_animation_section_params.

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 scope statement ('both are UMovieSceneSubSection') implicitly tells the agent this tool only applies to sub/shot sections, not arbitrary sections, but it never says when to prefer this over the closely-named siblings (set_section_range, set_skeletal_animation_section_params) nor any when-not conditions or prerequisites.

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