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

Annotations declare readOnlyHint=false and destructiveHint=false, and the description adds meaningful behavior beyond that: default layers (all), defaulted flags (no_tracks/no_vias/no_zone_fills all true), wildcard matching for remove, and enforcement by route_board and DRC. It doesn't disclose whether adds are additive or replace existing keepouts, leaving one notable gap.

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-loads the purpose in the first clause, then packs defaults, enforcement, and the remove behavior into tight sentences. It is dense but every sentence carries information; no filler.

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 write tool with no output schema, the description covers defaults, the rect/polygon shapes, layer targeting, enforcement, and removal semantics. It omits whether additions are additive versus replacing, and does not mention the wait_s job-follow-up behavior, which is a minor gap.

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 only 50%, but the description compensates by documenting defaults the schema omits (layers default to all; no_tracks/no_vias/no_zone_fills default true) and clarifying that remove takes names with wildcards. This adds genuine meaning over the raw 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?

States specific verbs (add/remove) plus the resource (keepout rule areas), and the body explains exactly what a keepout is and what it forbids. An agent can distinguish this from siblings like set_zones, set_design_rules, or route_board without opening the 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 clear context by explaining that route_board respects keepouts and KiCad DRC enforces them, which implies when they matter. It does not explicitly state when not to use this versus a sibling or any prerequisites, so it falls short of a full when/when-not/alternatives treatment.

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