set_fabric_physics

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

No annotations are present, so the description carries the full burden. It discloses the critical behavioral trait that every value is written and that defaults are CLO's documented defaults, not the fabric's current values – preventing a false assumption of partial updates. It also states what is preserved, but does not address side effects like reversibility or failure modes.

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?

Two tight opening sentences front-load the key behavioral caveat, then a clean per-parameter list follows. Every line adds information; no filler or repetition of schema titles.

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 15-parameter tool with no output schema and no annotations, the description is nearly complete: it defines the behavior, all parameters, and points to relevant sibling tools for reading values. The only gaps are unmentioned return/error behavior and explicit alternatives exclusion, which are often implied by the platform.

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?

With 0% schema description coverage, the description fully compensates by explaining all 15 parameters, including units (g/m2, mm), directional semantics (weft vs warp vs bias), and physical effects ('higher = stiffer, fewer folds'). This far exceeds the terse schema labels.

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?

Description opens with a specific verb+resource: 'Set all of a fabric's physical properties', which immediately distinguishes it from siblings like set_fabric_color, set_fabric_width, and set_fabric_information. It also specifies what is preserved (colour, texture, name), further scoping the tool's purpose.

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?

Provides clear operational context: CLO cannot report current values, so all values are written, which tells the agent what to expect when setting. It also points to get_fabric_info for reading values and add_fabric for library fabrics with measured physics, but does not explicitly state when not to use it versus siblings like set_fabric_information.

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