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

Annotations already declare destructiveHint=true and readOnlyHint=false, so the safety profile is partly covered. The description adds meaningful behavior beyond that: no vias are added or removed, pour-splitting changes are undone, and the board is kept only if KiCad counts nothing worse — a strong, non-obvious reversibility guarantee.

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?

It is front-loaded with the "After routing" trigger and every clause carries real information. The single sentence with deeply nested parentheticals is dense but not padded, only slightly harder to parse than an ideal structured form.

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 destructive mutation tool with annotations and fully-specified parameters, the description supplies the operation, its constraints, and its safety net. No output schema exists, so return values need not be explained; the async/job aspect is handled by the wait_s schema text.

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% — both design_id and wait_s are fully documented in the schema, including the running-status follow-up. The description adds no parameter-level meaning, so the baseline of 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?

The description states a specific, non-tautological purpose: redrawing routed runs into the fewest 0/45/90-degree segments and widening under-width tracks. It is clear what the tool does, though it never names overlapping siblings such as widen_nets, polish_vias, or cleanup_board, so the agent must infer the distinction.

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?

"After routing" gives a clear temporal cue for when this runs, which is genuinely useful context. However, there is no explicit when-not guidance and no mention of how this differs from or supersedes widen_nets/cleanup_board, leaving the choice between siblings to inference.

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