surface_ruled

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

With no annotations, the description does substantial work: it defines unit/expression handling, ruled_type semantics, direction requirements, atomic failure behavior ('nothing changed'), and the return structure. It does not mention permissions or idempotency, but covers most behavioral traits an agent needs.

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 front-loaded with the core operation, then organized into units, refs, follow-up actions, errors, returns, and a compact example. Every line carries actionable information without padding.

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 10-parameter, unannotated tool with no output schema, the description covers purpose, key parameter semantics, error conditions, return fields, and follow-up operations. Minor omissions like chain/alternate_face/corner behavior are already documented in the schema.

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 already 100%, so the baseline is 3. The description adds meaningful semantics beyond the schema: strings are expressions, ruled_type is measured against the edge face, direction follows the direction entity, and edge/curve refs come from specific sibling tools.

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 specific operation: creating a ruled surface as a strip of straight rulings grown from edges or sketch curve refs. This distinguishes it from siblings like surface_patch or surface_extend by naming the exact construction method and input sources.

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 clear contextual guidance: refs come from inspect_query and sketch_* tools, and the result should be closed with surface_stitch or thickened with body_thicken. It does not explicitly exclude alternative surface tools, but the intended workflow is clear.

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