nexez_validate_checkoutDry-run a checkout for an offer BEFORE paying - validates the offer, currency, and payment readiness. Never charges.
| Name | Required | Description | Default |
|---|---|---|---|
| slug | Yes | ||
| offer | Yes | e.g. services-0 or products-1 | |
| query | No | Optional buyer context | |
| buyerEmail | No | ||
| buyerReference | No | ||
| offerConfiguration | No | Canonical buyer values required by the target offer configuration schema. |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true and destructiveHint=false. The description adds the concrete guarantee 'Never charges' and specifies the validation scope (offer, currency, payment readiness), which enriches the annotation with operation-specific behavioral detail.
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, front-loaded sentence delivers purpose, timing, validations, and side-effect safety with zero filler. Every clause earns its place.
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 6 parameters, a nested object, no output schema, and no clarity on what 'slug' identifies or how to structure offerConfiguration, the description is too thin for an agent to reliably construct a correct call. The safety guarantees are clear, but the invocation details are not.
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 coverage is only 50% (3 of 6 params described), and the description adds no parameter-specific meaning. The required 'slug' is entirely undocumented in both schema and description, and there is no guidance on buyerEmail, buyerReference, or how to fill the nested offerConfiguration object.
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 ('Dry-run'/'validates') and resource ('a checkout for an offer'), with clear scope: 'BEFORE paying' and 'Never charges.' It also lists what is validated ('offer, currency, and payment readiness'), distinguishing it from sibling tools like directory/search/negotiation.
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 description clearly communicates when to use it — before payment, as a dry-run — and explicitly states a key non-condition: it never charges. It does not name alternative tools or give when-not-to-use exclusions, so it stops short of a 5.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Add one secure layer between your agents and this server.
Each tool targets a distinct action—browsing, fetching a manifest, searching, validating checkout, and validating negotiation. Directory and search both surface listings but are differentiated enough by browse vs. ranked search intent.
All tools share the nexez_ prefix and use snake_case, with most following a verb_noun pattern. nexez_directory is the one deviation since it uses a noun instead of a verb, but the overall pattern remains recognizable.
Five tools is well-scoped for a focused commerce discovery and validation server. Each tool serves a distinct purpose without unnecessary redundancy.
The toolset covers discovery, detail retrieval, and pre-transaction validation for checkout and negotiation. Actual payment execution and negotiation submission are not included, but the descriptions explicitly frame this as a validation-only surface, so the core workflow is well covered.