pcb_design_diff

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

With no annotations, the description carries full burden. It discloses the main behavior (comparing and reporting) and implies read-only operation via 'report'. However, it does not explicitly state that no modifications are made, nor does it specify what happens if no snapshot exists or the exact nature of the report.

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 sentence in Chinese, front-loaded with the core action and outcome. Every word adds value—no fluff or repetition of the tool name.

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?

The description explains the core function and lists the types of changes reported, but since there is no output schema, additional details about the report format or return value would be helpful. It also omits any prerequisites or error conditions, making it adequate but not fully complete for a simple tool.

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 tool has zero parameters, so the baseline is 4. The description correctly avoids adding parameter details because there are none, and the empty input schema requires no further explanation.

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 tool compares the current design with the last snapshot and reports added, removed, or moved components. It uses specific verbs ('compare', 'report') and a specific resource context, distinguishing it from sibling tools like pcb_design_snapshot (which likely creates snapshots) and pcb_get_state.

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 description implies usage for reviewing design changes since the last snapshot, but it does not explicitly state when to use this tool versus alternatives, nor does it mention prerequisites like the existence of a snapshot. Guidance is implicit rather than explicit.

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