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

Annotations mark this as a non-read-only, non-destructive write. Beyond that, the description adds genuinely useful behavior: the result is composited at full quality from the original files and the project stays editable so it can be flattened again. This non-destructive mutability is not conveyed by the annotations alone.

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?

Two tight sentences, front-loaded with the action and output, followed by the editability guarantee. No filler or repetition.

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 single-parameter tool with full schema coverage and no output schema, the description is nearly complete: it covers the action, the compositing quality, and the non-destructive guarantee. The only minor gap is what is returned (e.g., an asset id or the picture's location).

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?

Only one parameter (layer_set_id) and the schema documents it at 100% coverage, so the schema carries the parameter burden. The description adds nothing about the id beyond the schema's own text, making the baseline 3 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?

States a specific verb and resource: saving a layers project as a finished composited picture in the library. It also clarifies the source (original layer files) and destination (library), which helps distinguish it from export_layer_set, though it never names that sibling 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?

Implies usage (flatten when you want a finished picture) and notes the project remains editable, but it names no alternatives or when-not conditions. An agent still has to infer whether export_layer_set, get_layer_set, or stitched output is preferable for a given goal.

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