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

Annotations cover only the safety profile (readOnly, not destructive, openWorld), so the description carries the disclosure load and does so well: it enumerates the return payload (a single decision, per-part results, memory/M.2 slot limits, needed adapters, substitutions, blocking questions, evidence, signed receipt) and explains the verified-vs-unverified catalog behavior. This is exactly the context an agent needs beyond the structured hints.

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 core purpose is front-loaded, but the middle sentence is a very long catalog enumeration that reads more like a coverage dump than guidance. It is defensible for scoping, yet it bloats the definition and buries the usage instruction.

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?

Given a complex multi-item validation tool, the description covers inputs, decision output, and catalog boundaries, and the return values are also covered by the output schema (making their in-description listing redundant). The one real gap is sibling disambiguation among the many overlapping 'check/validate/verify' tools.

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 restates what the setup and purchase collections mean ('the setup the person owns (with current configuration) plus everything in the cart'), which adds a little framing but no syntax, ordering, or formatting detail beyond the schema.

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 opening clause gives a specific verb and scope: 'Check a whole purchase before recommending or ordering it,' followed by an explicit inventory of what is validated (owned setup + cart). This distinguishes it from single-item checkers like check_compatibility or check_fit. It does not, however, name siblings such as check_cart_before_checkout or recheck_plan, so the boundary is inferred rather than stated.

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?

It gives a clear usage context ('before recommending or ordering it') and defines the input shape (owned setup + everything in the cart, quantities included). There is no explicit when-not guidance or routing between itself and the overlapping siblings verify_receipt, check_cart_before_checkout, and recheck_plan.

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