pcb_calc_eye_diagram

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

No annotations are provided, so the description carries the burden. It discloses the modeling approach (lossy transmission line, conductor + dielectric loss) and outputs (eye opening, jitter, pass/fail). However, it does not mention assumptions like NRZ signaling, equalization, or the nature of jitter (e.g., random vs deterministic), nor the return format.

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 two sentences, front-loaded with the main function. Every sentence provides value: one states the core purpose, the other adds modeling and output detail. No filler or redundancy.

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 complex tool with 10 parameters, no output schema, and no annotations, the description is too brief. It gives a high-level summary but doesn't explain important aspects like the 'standard' parameter's role in selecting thresholds, the type of statistical analysis, or what the estimated jitter consists of. The partial output description (eye opening, jitter, pass/fail) is a start but insufficient for full behavioral expectation.

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 100%, so the baseline is 3. The description adds minimal parameter context, only implying that loss parameters (dielectric constant, loss tangent) are part of the lossy transmission line model. It doesn't tie specific parameters to the model behavior beyond what schema descriptions already state.

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 begins with 'Calculate statistical eye diagram for a high-speed serial channel,' a specific verb and resource. It further specifies the modeling approach (lossy transmission line with conductor and dielectric loss) distinguishing it from sibling tools like pcb_calc_ibis_eye, which likely uses IBIS models.

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 use for high-speed serial channel analysis but does not explicitly state when to use this tool versus alternatives such as pcb_calc_ibis_eye or pcb_calc_pcie_link_budget. No exclusions or when-not-to-use guidance is provided.

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