Set Comp

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

Annotations already declare the safety profile (destructiveHint=true, idempotentHint=true), so the bar is lower, and the description still adds real behavior: partial-update semantics, the work_area containment constraint, the motion_blur/frame_blending rendering dependency, and the shutter_angle default of 180. It does not explain what the destructive flag implies for existing layers or durations, which is the one notable gap.

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?

Dense and front-loaded: the partial-update rule leads, followed by constraints and defaults in priority order. Every clause carries information, though the semicolon-chained jargon is terse enough to be slightly hard to parse on first read.

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 13-parameter mutation tool with no output schema and zero schema-level documentation, the description covers the highest-risk fields and the update semantics but leaves most parameters and the destructive implications unexplained. Adequate to call safely, not complete.

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 0% across 13 parameters, so the description must carry the load and only partly does: it explains work_area, motion_blur, frame_blending, and shutter_angle's default. fps, name, width, height, bg_color, duration, pixel_aspect, and shutter_phase get no meaning beyond their names, and the nested work_area.start/duration fields are only indirectly covered.

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?

"Change comp settings" gives a specific verb and resource, and the partial-update clause pins down exactly what kind of mutation this is. It reads clearly against siblings like set_layer, set_property, and create_comp, though it never names an alternative explicitly.

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?

"only the fields you pass change" is genuinely useful invocation guidance that tells the agent this is a partial update rather than a full replacement. However, there is no when-to-use vs when-not guidance and no routing away from create_comp or set_item, so usage is only implied.

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