pcb_set_board_shape

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

With no annotations, the description carries the full burden and does disclose the key destructive trait ('Overwrites the current board shape'), plus units (mils) and the fact that corner order is irrelevant. It does not say what happens to existing parts/tracks now outside the new outline, which is the main remaining risk an agent needs.

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 the definition and the overwrite warning, then setup context, then parameters. The Args block slightly restates the schema titles but supplies units, so it earns its place; minor redundancy in the Returns line given an output schema exists.

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?

An output schema exists, so return details are optional, and units/ordering/setup timing are all covered. The gap is side effects on geometry and objects outside the new rectangle, which matters for a shape-overwriting mutation 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 0% (bare titles X1/Y1/X2/Y2), so the description must compensate, and it does: each parameter is identified as a corner coordinate, units are given as mils, and the pairs are stated to be opposite corners in any order. It adds no guidance on coordinate ranges or the board origin.

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 ('Define the physical PCB board outline') and constrains the shape to a rectangle, which separates it from pcb_auto_size_board_outline and pcb_get_board_outline. An agent can tell exactly what geometry this writes.

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?

"Use this right after creating a new PCB document to establish the board size before placing parts" gives a concrete trigger and ordering constraint. It does not name alternatives (e.g. pcb_auto_size_board_outline) or say when not to call it, so it falls short of a 5.

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