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

The annotations already establish that this is a non-read-only, non-destructive, closed-world mutation. The description adds meaningful context beyond that: default layer coverage, default boolean rule values, interaction with route_board and KiCad DRC, and wildcard support for removal. It does not fully explain what happens to existing keepout definitions on removal, but the annotation bar is lower here.

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?

Four dense sentences front-load the operation and then add only necessary detail about geometry, defaults, enforcement, and removal. Every sentence carries useful information, and nothing is redundant.

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 4-parameter mutation tool with no output schema, the description covers the core operations, default semantics, and enforcement behavior well enough to invoke it correctly. It does not discuss return values or job-follow-up behavior, though wait_s is explained in the schema.

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 only 50%, but the description compensates for several undocumented fields by explaining layer defaults, the default-true behavior of no_tracks/no_vias/no_zone_fills, and wildcard support for the remove/name fields. The remaining parameters (design_id, wait_s) are already described in the schema.

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 names the exact operation (add or remove), the resource (keepout rule areas), and defines what a keepout is, including its rect/polygon shape and layer scope. It is clearly distinct from zone-setting siblings in substance, though it does not explicitly name a sibling to contrast with.

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?

It clearly states the two modes (add, remove) and notes that remove accepts wildcards. However, it gives no explicit when-to-use guidance versus alternatives such as set_zones, nor any when-not-to-use conditions, leaving the agent to infer routing constraints and DRC enforcement as the rationale.

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