design_add_rock

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

With no annotations, the description carries the full burden, and it does add real value by disclosing the rendering behavior (depth-aware, silhouette, shadow, texture) and the available style dimensions. It stops short of stating whether this mutates the current sketch, adds to a layer stack, what is returned (e.g., a layer id), or whether the operation is reversible.

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?

Three tightly packed sentences, front-loaded with purpose before enumerating variants. The preset list is somewhat redundant with the schema enum but is short and scannable, so little is wasted.

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 zero-required-parameter creation tool with a fully documented schema and no output schema, the description gives enough style/behavior context to call it correctly. The main omission is the return value and where the layer lands in the document, but this is a minor gap given schema completeness.

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% and each of the 12 parameters is documented in-schema, so the baseline is 3. The description restates the rockType enum values, texture modes, and preset names without adding syntax, interaction, or defaulting semantics beyond what the schema already provides.

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 opens with a specific verb+resource ('Add a natural rock form layer') and enumerates the rock forms and texture modes it renders, so an agent knows exactly what this creates. It does not, however, distinguish itself from nearby siblings such as design_add_cliff_face or design_add_terrain_profile, leaving overlap for the agent to infer.

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?

There is no guidance on when to use this versus alternatives like design_add_cliff_face, design_add_terrain_profile, or the landscape scene composites, nor any stated prerequisite (e.g., an open sketch or active layer). The agent is left to infer applicability entirely from the tool name and field list.

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