fabric_material

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

With no annotations, the description carries the full burden, and it excels: it discloses that the operation 'May change scene or write files,' warns to 'Verify resulting state,' and explicitly states that a timeout leaves state UNKNOWN and requires reconciliation before retry. It also reveals the BACK/SIDE unlink behavior, going far beyond a basic read/set statement.

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?

Every sentence earns its place: purpose is front-loaded, followed by unlink behavior, version verification, read/set switch, a distinction from colorways, side-effect warnings, and timeout protocol. There is no filler or redundant wording.

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 no-annotation, no-output-schema tool with three parameters, the description is remarkably complete, covering semantics, side effects, read/set behavior, and error handling. The only minor gap is not explicitly describing the exact shape of a read result, though 'omit rgba to read' strongly implies it returns the current RGBA value.

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%, so the description must compensate. It fully explains face (FRONT/BACK/SIDE), rgba range (0..1), and the read/write toggle via omission of rgba. fabric_index is left to inference from its name, but the most semantically ambiguous parameters are well-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?

The description opens with 'Read/set FRONT/BACK/SIDE RGBA (0..1)', providing a specific verb and resource that immediately clarifies the tool's role as per-face material color manipulation. It also distinguishes the face enum from 'fabric assignment colorway options,' which differentiates it from sibling tools like assign_fabric.

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?

It gives explicit mode selection guidance ('Omit rgba to read'), explains the unlink side effect for BACK/SIDE, and points to reconcile_operation for timed-out operations. However, it does not name a specific alternative sibling for when a different tool should be used, aside from implicitly excluding fabric-assignment colorways.

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