fabric_apply

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

With no annotations provided, the description must carry the full behavioral burden. It states 'Add a fabric' implying a mutation, but does not disclose what happens to existing fabrics, whether the operation overwrites or merges, what 'pieces' refers to (since no such parameter exists), or any prerequisites such as needing a fabric library loaded. It also doesn't mention errors, reversibility, or return behavior. This is a significant gap for a mutating tool.

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?

The description is a single, information-dense sentence that front-loads the primary action and then adds the optional parameters. There is no fluff or repetition, and it manages to convey the accepted input forms for fabric. It loses a point because the density makes the missing 'patterns' parameter and the ambiguous 'pieces' reference more glaring, but the structure itself is efficient.

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?

Given no annotations, no output schema, and 0% schema description coverage, the description is expected to fully explain all parameters and usage context. It covers fabric, color, and texture_image, but completely omits the 'patterns' parameter, which appears in the schema but is unexplained. It also introduces 'pieces' without a schema property, leaving the agent to guess how to specify target pieces. No prerequisites, side effects, or return details are provided, making this inadequate for confident invocation.

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 the schema's lack of documentation. It provides useful examples for 'fabric' (keyword, library file, .zfab), 'color' (#hex or name), and 'texture_image' (base texture), but says nothing about 'patterns' (an array of strings), which is a required explanation. It also mentions 'pieces' as an assignment target without any corresponding schema parameter, creating confusion. The description is incomplete for the full parameter set.

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 states a clear verb-resource pair: 'Add a fabric... and assign it to the given pieces.' It specifies the types of fabric inputs (keyword, library file, .zfab path) and notes the default behavior (assign to all pieces). While it doesn't explicitly contrast with sibling tools like fabric_set_color or fabric_set_texture, the action of adding and assigning a fabric is distinct and unambiguous. It could be a 5 with explicit differentiation, but it's already quite clear.

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 description implies usage context by stating 'assign it to the given pieces (default: all)', which tells the agent when this tool is appropriate (when applying a fabric to pieces). However, it gives no explicit guidance on when to use this tool versus alternatives such as fabric_library, fabric_list, fabric_set_color, or fabric_set_texture. There are no exclusions or conditional instructions, so the agent must infer that this is the primary fabric-assignment tool. That is sufficient but not exemplary.

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