Thicken Surface

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

Annotations already declare readOnlyHint=false, idempotentHint=false, and destructiveHint=false, so the agent knows this is a non-idempotent mutation. The description adds a useful unit convention (cm/degrees by default) beyond the annotations, but says nothing about what happens to the source surface body, reversibility, or required preconditions.

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 compact sentences with the core action front-loaded and the unit caveat immediately after. No filler, though the definition is arguably a touch terse given the gaps it leaves.

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 3-parameter mutation tool with no output schema, the definition covers the core action and units but omits what an agent most needs: whether the original surface is consumed, what the direction modes do, and what the call returns. Annotations carry the safety profile, keeping this from being inadequate, but gaps remain.

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 only 33% – thickness has a description, but body_name and direction are undocumented. The unit sentence ('lengths and coordinates are in cm ... angles in degrees') clarifies thickness units beyond the schema, which is genuine added value, but there is no explanation of body_name expectations or the direction enum's effect.

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 resource ('Thicken a surface body into a solid'), so the agent knows exactly what operation is performed. It does not explicitly name a sibling or differentiate from similar surface tools like stitch_surfaces or patch_surface, but the purpose itself is unambiguous.

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 offers no when-to-use context, no prerequisites (e.g. that a surface body must exist), and no routing to alternatives. The only guidance is a unit convention, which is not usage guidance about selecting this tool.

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