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

Annotations already cover the safety profile (readOnly/idempotent/openWorld), and the description piles on genuinely non-obvious behavior: Fast Extraction routes page scout + deterministic readers, the deep engine may re-run a module as `monolith_rescue` and is billed as delivered, rescues can take minutes, and only a double failure yields status FAILED. That is exactly the kind of cost/latency/failure-mode context an agent cannot get from annotations.

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?

Purpose and the extract_pinout routing come first, then engine/timeout/failure details, which is the right order. The engine paragraph is long but every clause carries decision-relevant information (latency, billing, timeout, failure status); only mild tightening would improve it.

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?

With an output schema present, the description needn't explain return values, and it covers what the schema cannot: extraction depth, fallback path, latency expectations, billing, and terminal failure semantics. Nothing an agent needs in order to call this correctly is missing.

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% and both parameters (documentPath, partName) are already well documented in the schema, including the https-only vs local-stdio distinction. The description adds no parameter-level meaning beyond that, so the baseline 3 applies.

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 ('Extract') plus a concrete resource list — package outline dimensions D, E, A, A1, e, L, b — and a nominal IPC-7351B-style land geometry estimate, with an explicit caveat that it is review-level, not a manufacturer land pattern. It also distinguishes itself from the sibling extract_pinout by scope, so an agent can route between them without opening either schema.

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?

Names the alternative explicitly ('For the package variant/pin count from the pin table, prefer extract_pinout'), giving a concrete condition that selects the sibling over this tool. It also gives operational guidance (set a 10-minute client timeout due to rescue). It stops short of a full when-not-to-use statement for the dimensions case itself, so a 4 rather than a 5.

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