add_landscape_layer_blend_node

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

Goes well beyond the annotations by disclosing that the node arrives with layer inputs but no incoming connections, and by flagging the silent failure mode where mismatched names 'read zero weight forever.' It does not address duplicate-call behavior, which matters given idempotentHint=false, so it falls just short of full coverage.

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-loaded with the action and effect, followed by prerequisite, wiring steps, and a Returns block that substitutes for the absent output schema. The 'grass, rock, sand and snow' illustration is the one soft sentence in an otherwise dense definition.

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?

With no output schema, the description supplies the return shape (material_path, expression_id, layer_count, layers) and covers the prerequisite chain and next steps, which is close to complete for a graph-mutation tool. It omits what happens when the node is added twice or how it interacts with an existing blend node in the material.

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 already 100%, so the baseline is 3, but the description adds real meaning: layer_names maps one-to-one onto generated blend inputs, and blend_type selects weight/alpha/height blending rather than merely being an enum string. It still does not explain pos_x/pos_y defaults beyond what the schema states.

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 ('Add the LandscapeLayerBlend node that makes a terrain material multi-layered') plus its scope ('pre-populated with one input per name in layer_names'). It is clearly distinguishable from neighbors such as add_landscape_layer (terrain registration) and create_material_layer_blend (a different node type) because the description explains the node's material-graph role.

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?

Explicitly names the prerequisite and the alternative tool that must run first ('layer names must match the ones registered on the terrain with add_landscape_layer'), and then sequences the follow-up work: 'wire each layer's texture chain with connect_material_expressions, then compile_material and check get_material_stats.' An agent knows exactly when to reach for this and what to do next.

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