pcb_net_stats

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

Annotations already declare the safe read-only/idempotent profile, so the bar is lower; the description adds real value by disclosing special output behaviors (a hint when a net has pads but no tracks, differential-pair candidate detection) and that it operates on the currently open board. It omits the default result cap (200) and any truncation behavior, which an agent should know.

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?

A single front-loaded sentence with no filler; every listed item corresponds to a returned metric. It is somewhat list-dense, but nothing is wasted.

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?

With an output schema present, return values need not be re-explained, and annotations cover the safety profile. The definition is nearly complete for a read-only stats query; the main gap is that truncation/default-limit behavior is never surfaced to the caller.

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 67%: the `net` and `board_path` params carry descriptions while `limit` is documented only by its default/min/max constraints. The description mentions no parameters at all, so it adds nothing beyond the schema — baseline 3 is appropriate.

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 resource ('per-net routing statistics from the open board') and enumerates the exact metrics returned: track count/length, widths, layers, vias, pads, pad-without-track hints, and differential-pair mismatch. The 'per-net' framing separates it from board-level siblings like pcb_summary and review_board.

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 never says when to reach for this tool versus alternatives such as pcb_summary, route_check, or impedance_calc, nor any preconditions beyond the implicit 'open board'. Usage must be inferred entirely from the purpose text.

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