check_length_match

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the agent knows this is a safe, repeatable read. The description adds that lengths are compared 'against the longest', which clarifies the reference point, but says nothing about the tolerance behavior or output.

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?

A single well-formed sentence with the core action front-loaded and no filler. It is efficient, though the terse phrasing leaves semantic gaps that a second sentence could have closed.

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?

No output schema exists, so the description should explain what a check returns (boolean, list of mismatches, measured deltas), but it does not. Combined with 0% parameter coverage, an agent cannot reliably predict inputs or outputs.

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 carries the full burden for both parameters. It implies 'nets' is the group being compared but never explains 'tolerance_mm' at all — a critical parameter whose semantics (allowed deviation from the longest) are left entirely undefined.

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?

States a specific verb (compare) and resource (routed lengths of a group of nets) with a clarifying example (bus or lanes). An agent can tell what it does without opening the schema, though it doesn't explicitly differentiate itself from potential siblings like check_impedance.

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 parenthetical 'e.g. a bus or lanes' implies the length-matching use case, which is genuine context. However, there is no explicit when-to-use/when-not guidance and no named alternative, so usage must be inferred.

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