pcb_canvas_origin

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

Annotations already declare idempotentHint=true, destructiveHint=false, readOnlyHint=false, so the safety profile is known. The description adds useful context on coordinate units and frame, which is valuable. It doesn't state what happens to existing content when the origin is changed or whether the change persists to file, so it goes modestly beyond annotations without fully covering behavioral effects.

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?

Four sentences, front-loaded with the core purpose, followed by units/frame then alternative routing. No filler; each sentence carries meaning, though the explicit sentence recommending use of this tool to read/set the offset is somewhat redundant with the opening sentence.

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 get/set origin tool with no output schema, the description gives units, coordinate frame, and the alternative conversion tool – enough for an agent to call it correctly. It doesn't describe the return shape for the 'get' action or persistence semantics, which are minor given annotations and schema coverage.

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 the schema already documents all five parameters. The description adds a coordinate-frame contract (mil, +X rightward, +Y upward) that supplements the plain offsetX/offsetY parameter descriptions, but does not expand on 'action', 'document', or 'instance_id' beyond what the schema says. Baseline 3 is correct.

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+resource ('canvas origin offset relative to data origin') and distinguishes its get/set dual behavior. The units and coordinate frame (+X rightward, +Y upward, mil) make it unambiguous compared to siblings like pcb_convert_coordinates.

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?

Explicitly names the sibling pcb_convert_coordinates and the condition that selects it ('to convert between canvas and data coordinates'), giving clear alternative routing. It does not spell out when to prefer 'get' vs 'set', but the action enum in the schema covers that.

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