eda_pcb_primitive_fill_modify

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

The description discloses that the return value is the fill primitive object or `undefined` to indicate failure, which is useful behavioral information. However, it does not mention side effects, mutability constraints, or destructive implications, and with no annotations the description carries the full burden but offers minimal context. No contradiction with annotations (none provided).

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?

The description is a single concise line with the signature, a Chinese one-liner meaning, and a return note. It is front-loaded and contains no filler, effectively communicating the core information without redundant elaboration.

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?

With no output schema, no annotations, and a sparse wrapper schema, the description provides the signature but omits critical context such as required vs optional properties, valid values for fields like `fillMode`, and usage examples. Given the nested `property` object, an agent needs more information to invoke the tool 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?

The schema only defines generic `args` and `windowId` wrappers, while the description provides the full TypeScript-style signature listing `primitiveId` and a `property` object with six fields and their types. This adds substantial meaning beyond the schema, though it does not explain the semantics of each property value, such as valid enums for `fillMode` or required fields.

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 clearly states the operation as 'pcb_PrimitiveFill.modify' with a full type signature and Chinese summary '修改填充', making its purpose unambiguous. It precisely identifies the action (modify) and resource (PCB primitive fill), distinguishing it from sibling modify tools without confusion.

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?

No guidance is provided about when to use this tool instead of alternatives. The description only gives the signature and return note, with no mention of prerequisites, selection criteria, or comparison to similar tools like eda_pcb_primitive_region_modify. An agent would have to infer usage only from the name.

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