assembly_analyze_interference

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

With no annotations, the description carries the full burden and does: it declares the operation is read-only in effect ('nothing is added to the design'), discloses a performance cost ('the full check is slow'), defines the default exclusion of merely-touching parts, and specifies the failure condition. That is a complete behavioral profile for a query tool.

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?

Front-loaded with purpose, then constraints, then return shape; each sentence carries information an agent needs to call it correctly. The inline return-shape block and the worked example overlap slightly, costing a bit of tightness, but neither is 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?

No output schema exists, so the description supplies the full response contract — `checked`, `count`, and the interference entries with volume and bbox fields — plus a worked example. Combined with the parameter and cost guidance, an agent has everything needed to invoke and interpret it.

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 100%, so baseline is 3, but the description adds real meaning: it explains that omitting `items` checks every occurrence plus root bodies, that `items` is the escape hatch for large assemblies, and that the minimum of two items is enforced with INVALID_PARAMS. It doesn't add format details on occurrence path syntax beyond what the schema already states.

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 ('Check whether parts overlap') plus the exact payload returned (overlap volume in mm³ and bounding box in mm). It is clearly distinguishable from sibling measurement tools like measure_distance or inspect_bounding_box because it reports pairwise interference rather than single measurements.

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?

Gives concrete when-to-use guidance: pass `items` on big assemblies because the full check is slow, and set include_coincident_faces=true only if touching parts matter. The error threshold (fewer than two items -> INVALID_PARAMS) is also stated. It stops short of naming a sibling alternative for simpler proximity questions, which is why it isn't a 5.

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