pcb_place_vias

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

With no annotations, the description carries the full burden and does substantial work: it discloses the batching model (one PreProcess/PostProcess and one broadcast), the coordinate fidelity guarantee (sub-mil decimals preserved), and the failure-reporting contract (placed/failed counts, unknown_layers). It omits prerequisites such as needing an active PCB document, whether the operation is undoable, and what happens when a layer pair fails to resolve beyond reporting it.

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 selection rule before any mechanics, then Args/Returns in a predictable structure. Every sentence carries information — the decimal-preservation note justifies the design rather than padding it.

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 single-parameter mutation tool with a 0%-coverage nested schema and an output schema, the description supplies what the schema cannot (per-key semantics) and what the annotations cannot (batch/broadcast behavior, failure counts). Nothing needed to call it correctly is missing; return values are covered by the output schema and briefly summarized.

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% — the schema is only an untyped array of open objects — so the description must compensate, and it does: every key is named with units (mils), defaults (size 50, hole_size 28, low_layer TopLayer, high_layer BottomLayer), required vs optional status (x/y required, net optional with empty meaning no net). This is meaning the agent could not obtain from the schema at all.

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 concrete verb and resource (place vias on the active PCB) plus a differentiating scale/mechanism (many vias in ONE IPC round-trip), and explicitly contrasts with the nearest sibling pcb_place_via. An agent can tell this apart from the single-via tool without opening either schema.

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?

Gives an explicit selection rule: prefer this over ``pcb_place_via`` whenever there is more than one via. That is a clear when-to-use with a named alternative. It does not address the other overlapping siblings (pcb_place_via_array, pcb_place_stitching_vias) or state when this tool should not be used, so it stops short of a full routing rule.

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