lay_flat

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

With no annotations, the description carries the full burden and does well on the core behavior: it defines how coplanar triangles are grouped into a face and adds the center-of-mass filter that prevents thin fins from being selected — genuine algorithmic disclosure an agent could not get from the schema. It stops short of saying whether the STL is rewritten in place or a rotated copy is produced, and says nothing about 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 sentences, no filler, with the resulting orientation (Z=0) front-loaded and the face-selection caveat second. Every clause contributes information an agent needs.

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 single-parameter geometry transform with no annotations and no output schema, the description should say what the agent gets back or what side effect occurs (file overwritten vs returned geometry). The rotation logic is fully covered, but the post-call state is not, leaving an operational gap.

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?

Only one parameter, `stl_path`, and the schema documents it at 100% coverage, so the parameter baseline of 3 applies. The description adds no meaning about the path (relative vs absolute, file must exist, whether the source is mutated).

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 and transformation: rotate the model so its largest flat face lies on the XY plane (Z=0), with the selection rule spelled out. The purpose is unambiguous and functionally distinct from the generic `rotate_stl` sibling, but that sibling is never named, so the agent must infer the difference rather than being told.

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?

Usage is implied by the operation itself (orienting a model flat, presumably for printing/prep), but there is no explicit when-to-use, when-not-to-use, or pointer to alternatives like `rotate_stl` or `center_model`. The fin exclusion is a selection caveat, not usage guidance.

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