Boolean Operation

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

Adds real value beyond the sparse annotations (readOnly=false, idempotent=false, destructive=false): it discloses that Fusion silently discards the tool body's geometry on a non-touching join and that the tool instead refuses proactively and reports the minimum distance. This failure-mode disclosure is exactly the kind of context annotations cannot carry.

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, front-loaded with the operation and modes, then the one non-obvious precondition. No filler, and the parenthetical failure explanation earns its length by preventing a silent-success trap.

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?

A destructive-in-effect modeling operation with no output schema and zero schema documentation is partially covered: the join-touch pitfall is handled, but cut/intersect behavior, body consumption, and result/report format are left unspecified.

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 0%, so the description must compensate. It names target_body and tool_body and states their required relationship for join, and its operation vocabulary matches the enum, but it never explains what happens to the tool body (consumed?), the default mode, or how target vs tool roles differ for cut/intersect.

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 (combine), the exact resource (two named bodies), and enumerates the three modes (join/cut/intersect), which maps 1:1 to the schema enum. It is clearly separable from neighbors like split_body, mirror, or loft.

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 an important precondition for the 'join' mode (bodies must touch or overlap), but there is no guidance on when to choose join vs cut vs intersect, nor on prerequisites such as selecting bodies in the same component. Usage is implied by the mode names rather than explained.

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