Apply Prop Materials

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

Annotations already declare destructiveHint=true and idempotentHint=true, so the description adds value by disclosing the approval gate and that other materials, painted pixels and geometry are preserved — softening the practical blast radius of a destructive update. It does not mention retry/idempotency behavior, though the schema's request_id field covers that.

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?

Four short sentences, front-loaded with the action and resource, then precondition, partial-update rule and approval gate. No filler and nothing that could be trimmed without losing 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?

With a rich schema, an output schema and detailed annotations, the description supplies the remaining operational essentials: prerequisite inspection, preservation guarantees and approval requirement. Minor gaps (what happens when a supplied material name doesn't exist, how to recover via undo/get_operation) are not covered.

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; the description goes beyond it by instructing 'supply only the names/colors to update' (confirming partial-update semantics) and by requiring that names be real material names read from inspect_project, a constraint the schema's pattern does not express.

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: 'propose changing named colors on an existing VoxelFlow prop.' The scope (existing prop, named colors only) is clear, but it never explicitly distinguishes itself from the sibling tool apply_materials, leaving the model-vs-prop split to inference from the name.

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?

Gives a concrete precondition ('First inspect_project to read its actual material names') and workflow context ('Requires Blockbench approval'), which tells the agent how to sequence the call. It stops short of naming when to prefer this over apply_materials or when not to call it at all.

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