pcb_place_fill

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

No annotations are provided, so the description carries the full behavioral burden. It discloses that this is a write operation creating a solid copper rectangle and that net assignment is optional, but it omits important behavior such as whether existing polygons need repouring, whether the net must already exist, and whether DRC runs automatically.

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?

The description is front-loaded with the core action, followed by a brief use-case sentence and a compact Args/Returns block. Every sentence is relevant, though the Returns section is somewhat redundant because 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?

For a moderate-complexity PCB mutation tool with six parameters, an output schema, and no annotations, the description covers the effect, all argument semantics, units, and return shape. It is callable as written, though it lacks richer behavioral context about polygon repour side effects and prerequisites.

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 0%, so the description must compensate. It documents all six parameters, including the crucial units ('X in mils'), the layer default ('TopLayer'), and the optional net behavior ('empty = no net'). This adds substantial meaning beyond the bare schema titles.

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: 'Place a rectangular copper fill on the active PCB.' It also clarifies the object type ('solid copper rectangle') and common uses. It does not distinguish this from close siblings such as pcb_place_polygon_rect or pcb_place_region.

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 implied usage guidance by naming thermal pads, ground planes, and copper pours. However, it does not say when to choose this over pcb_place_polygon_rect, pcb_place_region, or pcb_repour_polygons, nor does it state any prerequisites or exclusions.

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