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

Goes well beyond the annotations (readOnlyHint/openWorldHint/idempotentHint): it discloses that answers are grounded only in public balford.net material, carry numbered citations with source pages, and that the tool will refuse pricing, lead-time guarantees, unheld certifications, and customer-drawing content. It also disclaims that output is not a quotation, certification claim, or dimensional acceptance — exactly the behavioral context an agent needs before relying on the result.

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 usage are front-loaded well, but the text is repetitive: 'Returns a written answer with numbered citations plus the source pages' is restated later as 'Answers are assembled from Balford's own published engineering material and cite the page each claim came from,' and the public-source constraint is stated three times. Several sentences do not earn their place, which is what keeps this below a 4.

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, annotations covering the safety profile, and 100% schema coverage, the description supplies everything left: domain scope, grounding rules, citation behavior, and explicit refusal boundaries. Nothing an agent needs in order to call and interpret this tool 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% for both parameters (question with maxLength 600, lang with BCP-47 default 'en'), so the schema already carries the parameter semantics. The description adds nothing about the parameters themselves, so the baseline 3 is appropriate.

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+resource: 'Answer a metalworking engineering or sourcing question from Balford's own published engineering material.' The Q&A framing is unmistakably different from the sibling tools list_engineering_topics and search_balford_material, and the scope (fine blanking, ironing deep drawing, tolerances, DFM, RFQ prep) is enumerated so an agent knows the domain without opening a 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?

Gives explicit when-to-use phrasings ('how do I', 'what is', 'which process fits', 'what do you need for an RFQ') and explicit when-not boundaries (no price, no lead-time guarantee, no certification it does not hold, nothing from a customer drawing). Alternatives are not named by tool, but the trigger conditions and exclusions are specific enough that routing is unambiguous.

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