Point: Intersection (deterministic)

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

Annotations already provide readOnlyHint=true, so safety is covered. The description adds meaningful behavioral context: deterministic candidate selection via ref_x/ref_y and the returned shape {x, y}. It does not specify what happens with parallel/disjoint entities, but the core behavior is transparent enough.

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?

Three compact sentences with no filler. The primary operation is front-loaded, supported types are listed, the tie-breaking rule is stated, and the return shape is clearly given.

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 read-only geometric computation with a 100%-documented schema and a stated return shape, the description covers the essential selection and output behavior. No critical information needed to call the tool correctly is missing.

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 description coverage is 100%, and the schema already documents handle1/handle2 as LINE or CIRCLE and ref_x/ref_y as candidate selectors. The description reinforces the nearest-candidate behavior but does not add meaning beyond the schema.

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 uses a specific verb ('Compute') and resource ('intersection of two geometry entities') with explicit supported combinations (LINE-LINE, LINE-CIRCLE, CIRCLE-CIRCLE). It clearly distinguishes this from geometric-point siblings like point_from_snap and point_tangent.

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 usage context is implied: call this when you need a geometric intersection of supported entity pairs. It explains the reference-point selection condition but does not explicitly name alternatives or state when not to use this tool.

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