fabric_set_color

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

No annotations are provided, so the description carries the full disclosure burden. It makes the mutating nature of the operation clear and documents accepted color formats, which is useful. It does not, however, disclose downstream consequences (e.g., whether already-applied garments update), behavior on invalid color input, or reversibility.

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?

A single 17-word sentence with no filler. The operation and target are front-loaded, and the parenthetical value-format note earns its place as it directly informs how to fill the `color` parameter. Nothing 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?

For a simple 2-parameter setter with no output schema and no annotations, the description covers purpose and color format adequately. Remaining gaps include the unexplained fabric_index provenance, lack of sibling differentiation, and no error/edge-case behavior. It's sufficient for an agent to make an educated guess, but not fully self-contained.

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 for both parameters. It fully documents `color` by specifying '#hex' or colour name formats, but gives no guidance on `fabric_index` — where to obtain it, what it points at, or its zero-based vs one-based nature — beyond the weak hint 'already in the project'. Compensation is only partial.

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 ('Set') and resource ('base colour of a fabric already in the project'), and adds precision by specifying accepted value formats ('#hex' or colour name). The scope qualifier 'already in the project' meaningfully narrows the operation. However, it doesn't explicitly contrast with siblings like fabric_set_texture or fabric_apply, leaving differentiation implicit rather than stated.

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?

The phrase 'already in the project' implies a prerequisite — the fabric must exist before calling — which offers some contextual guidance. But there is no explicit when-to-use guidance, no mention of alternatives (e.g., fabric_library for adding fabrics, fabric_set_texture for texture), and no indication that fabric_index likely comes from fabric_list. Usage context is implied, not stated.

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