Add schematic rectangle

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

Annotations cover the mutation profile (readOnlyHint=false, idempotentHint=false), so the bar is lower. The description adds genuinely useful non-schematic behavior — 'Cosmetic only', meaning no electrical/netlist impact — plus the top-left anchoring convention and the fillColor="none" semantic. It does not mention the confirmWrite gate, but that is documented in the schema.

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?

Three tight sentences with zero filler; the purpose is front-loaded, then the cosmetic constraint, then the two most ambiguous parameter semantics. Every sentence earns its place.

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?

An output schema exists so return-value description is unnecessary, and the description covers purpose, cosmetic-only behavior, and key geometry semantics. With 12 parameters at 42% schema coverage, several numeric/optional parameters remain undocumented, which is the only material 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 description coverage is only 42% across 12 parameters, so the description must compensate. It adds real meaning for x/y (top-left corner) and fillColor ("none" = unfilled), but leaves lineType, rotation, fillStyle, lineWidth, and cornerRadius completely unexplained in both places — only a fraction of the gap is closed.

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 (Draw) and resource (rectangle on the schematic sheet) and immediately names the intent — section dividers/grouping boxes for functional blocks. Its cosmetic-drawing role clearly distinguishes it from siblings like add_wire, add_text, and place_component.

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 for when to use it (organizing a busy schematic into labeled blocks) and a concrete companion action ('pair with add_text for the title'), plus the critical constraint 'Cosmetic only'. It stops short of explicit when-not-to-use guidance, but the usage context is unambiguous.

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