analyze_length_group

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

With no annotations, the description carries the full burden. It discloses a key behavioral trait: distances are always in millimetres, regardless of document units. However, it does not state whether the operation is read-only, what happens if nets are unrouted, or any error behavior. The unit disclosure is useful but leaves other aspects unspecified.

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 core purpose and then a valuable unit caveat. Every clause adds information without redundancy, achieving high efficiency.

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 values need not be explained. However, the description does not explain the optional parameters (path, tolerance_mm) or their interaction with the tool's behavior. For a tool with three parameters, the description is too sparse to fully support correct invocation without additional assumptions.

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 0%, so the description must compensate. It only references 'nets' indirectly through 'explicit group of nets' and does not explain the meaning or purpose of 'path' or 'tolerance_mm'. The parameter names in the schema are minimally informative, but the description adds no clarity for the optional parameters.

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 uses a specific verb ('compare') and resource ('routed geometric lengths for an explicit group of nets'), clearly distinguishing it from siblings like measure_net_lengths (which measures individual nets) and analyze_differential_pair (which targets differential pairs). The scope is explicit: the tool operates on a user-specified group of nets.

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 phrase 'for an explicit group of nets' implies when to use this tool (when you have a specific set of nets to compare), but there is no explicit guidance on when not to use it or how it compares to alternatives such as measure_net_lengths or analyze_differential_pair. The context is clear but exclusions are absent.

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