tune_diff_pair_length

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

With no annotations provided, the description must disclose behavioral effects. 'Write matched-length rules' implies a mutation, but it does not state whether existing rules are overwritten, how the rules are applied to the board, or any side effects on DRC. No prerequisites or reversibility information is given.

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 that is front-loaded with the verb and object. No unnecessary words or repetition of schema fields.

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 tool is simple (3 params, no nested objects) and has an output schema, so return values are covered. However, with no annotations and no such detail in the description, the tool lacks behavioral context: side effects, prerequisites, and relationship to other tuning/checking tools. The description is too terse for a mutation operation.

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 0%, so the description must compensate. It clarifies that both net names refer to the positive and negative nets of the differential pair, and that the target length is the matched length to be applied to both. However, it does not explain units (though the parameter name implies mm) or whether the target is exact, minimum, or maximum.

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 writes matched-length rules for both nets in a differential pair. It uses a specific verb ('write') and resource ('matched-length rules for both nets'), distinguishing it from sibling tools like tune_track_length or route_tune_length which target single-ended traces.

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 differential pair length matching by specifying 'both nets in a differential pair'. It provides clear context but does not explicitly mention when not to use it or name alternatives like si_validate_length_matching or route_differential_pair, so it falls just short of full guidance.

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