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

Discloses the key behavioral fact that existing Edge.Cuts content is wiped ('Replace everything'), which annotations alone do not convey. That sits in mild tension with destructiveHint=false and the description adds nothing about async job behavior, defaults (line_width_mm), or what happens on failure — those behaviors live only in the wait_s schema text.

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 that leads with the verb and target layer, then the modes. It is dense with nested parentheticals but every clause supplies selection-relevant detail; nothing is padding.

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 mutation tool with no output schema, the description covers shape inputs and mutual exclusivity but not the return path (job / status / polling via get_board_job), the default line width, or failure handling. An agent would still need the schema to call this correctly.

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?

With schema coverage at 33%, the description carries real weight: it explains rect with optional corner_radius_mm, polygon as a point list, and fit_to_parts as the courtyard bounding rectangle plus margin_mm. It does not mention wait_s, line_width_mm, or design_id, but those are documented in the schema, so the gap is small.

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 verb and resource ('Replace everything on Edge.Cuts') and enumerates the three accepted outline forms (rect, polygon, fit_to_parts). Naming Edge.Cuts cleanly separates it from the set_keepouts / set_zones / set_silkscreen siblings without needing to reference them.

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 closing 'Give exactly one' is a useful exclusivity rule for the three modes, and each mode is described well enough to choose between them. However, there is no guidance on when to use this tool versus related siblings, no prerequisites (e.g., existing design state, required permissions), and no note on whether the change is reversible.

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