pcb_create_pad

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

Annotations already declare this as a non-read-only, non-idempotent, non-destructive write. The description adds the coordinate origin and unit semantics, which go beyond the annotations, but it says nothing about atomicity, repeat-invocation behavior (relevant given idempotentHint=false), or failure modes.

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, all front-loaded with the action first and coordinate semantics second; each sentence carries information the schema lacks. No wasted filler, though it is slightly longer than strictly necessary.

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 mutation tool with no output schema, the description covers the highest-risk ambiguity (units and coordinate reference frame) and routes to helper tools. It is close to complete, missing only a note on return/failure behavior, which is minor given the annotation 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 baseline is 3, but the description meaningfully adds unit and axis semantics (mil units, +X rightward, +Y upward, relative to canvas origin) that the terse schema ('X coordinate') does not convey. That extra meaning pushes it above baseline.

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 ('Create a standalone pad on the PCB'), and the word 'standalone' usefully hints this is a free pad rather than one owned by a footprint. It does not explicitly differentiate itself from creation siblings like pcb_create_via or pcb_create_track, so it falls just short of a 5.

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 description gives genuine usage context by pointing to pcb_canvas_origin and pcb_convert_coordinates for handling the coordinate system, which is the main source of error here. However it offers no explicit when-to-use vs when-not guidance or alternatives for the creation act itself, leaving that implied.

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