pcb_get_primitive_at_point

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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false, and openWorldHint=false, so safety is covered. The description adds genuinely useful behavioral context on the coordinate system and units, but says nothing about what happens when no primitive exists at the point, which primitive wins if several overlap, or what the call returns (no output schema).

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 tight sentences, purpose front-loaded, followed by the unit/orientation contract and then related-tool pointers. No filler, though the coordinate-convention block is somewhat dense relative to the core operation.

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?

The coordinate and unit semantics are fully covered, and the document/instance_id parameters are documented in the schema. What is missing is the return contract: with no output schema, the description should say what is returned (and what happens on a miss), which is the main remaining gap for a point-query tool.

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; the description goes beyond the schema's bare 'X coordinate'/'Y coordinate' by specifying units (mil, 1 mil = 0.001 inch) and axis orientation (+X rightward, +Y upward). This resolves a real ambiguity an agent would otherwise guess at.

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 (Get) and resource (primitive) with a precise spatial scope (at a specific point on the PCB), which inherently separates it from pcb_get_all_primitives, pcb_get_primitives_by_id, and pcb_get_primitives_in_region. It does not, however, explicitly name or contrast any sibling, so an agent must infer the boundary.

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 coordinate explanation: you call this when you have a PCB canvas point. The only routing guidance given is for coordinate handling (pcb_canvas_origin, pcb_convert_coordinates), not for choosing this tool over the other primitive-retrieval siblings.

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