build_cartReturns one natureswildberry.com link that fills the shopper's cart with the chosen variants, one-time or Subscribe and Save, a line-by-line summary and the store's Shopify agent checkout endpoint (which does not support subscriptions). Nothing is bought until the shopper checks out. Read-only.
| Name | Required | Description | Default |
|---|---|---|---|
| items | Yes | The items for the cart |
Changes observed during successful MCP inspections.
Input schema / $schemaRemoved value: -"http://json-schema.org/draft-07/schema#"Input schema / properties / items / items / properties / variant_id / exclusiveMinimumRemoved value: -0Input schema / properties / items / items / properties / variant_id / minimumAdded value: +1Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnly, idempotent, non-destructive, open-world. The description adds genuine context beyond that: 'Nothing is bought until the shopper checks out', the return includes a line-by-line summary and a Shopify agent checkout endpoint, and that endpoint excludes subscriptions. Slight redundancy restating 'Read-only' costs a little.
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?
Effectively a single dense sentence, front-loaded with what is returned (the link) before the caveats. It earns its length, though the trailing 'Read-only.' is redundant with the annotation.
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 carries the return-value burden and does so by naming the link, a line-by-line summary, and the checkout endpoint. It covers the essential behavioral caveats; only a stronger when-to-use cue 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 coverage is 100%, so the schema already documents items, quantity (1-10), subscribe, and variant_id. The description echoes the one-time vs Subscribe-and-Save distinction but adds no format or constraint detail beyond the schema. 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?
Specific verb+resource: returns a natureswildberry.com cart-fill link for chosen variants. It clearly distinguishes itself from siblings like get_products and recommend_product by describing its unique output (a cart link plus checkout endpoint).
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 implies the tool is used after selecting variants (one-time or Subscribe and Save), and notes the checkout endpoint does not support subscriptions. But it never explicitly states when to reach for this tool versus siblings like get_products (which supplies variant_id). Usage is inferable rather than stated.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
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