discover-storeDiscover available shopping tools on a UCP-enabled store.
Connects to the store's MCP endpoint and lists all available
tools (search, cart, shipping, etc.). Use this to understand
what a store supports before shopping.
Example: domain: "allbirds.com"| Name | Required | Description | Default |
|---|---|---|---|
| domain | Yes | The store domain to discover (e.g., "allbirds.com") |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations declare readOnlyHint=true, and the description adds meaningful behavioral context by stating it 'Connects to the store's MCP endpoint' and 'lists all available tools.' This reveals a remote network behavior and expected output beyond what the annotation alone conveys, with no contradiction.
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 description is compact, front-loaded with the core purpose, and every sentence contributes: purpose, behavioral detail, usage context, and an example. No filler or digression.
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?
For a one-parameter read-only tool, the description covers the purpose, connection behavior, and output ('lists all available tools'). It does not define 'UCP-enabled' or discuss error cases for unsupported domains, but an agent has enough information to select and invoke the tool correctly.
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%, with the domain parameter already documented including the allbirds.com example. The description repeats the same example and adds no new parameter semantics beyond what the schema already provides.
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 states a specific verb ('Discover') and resource ('available shopping tools on a UCP-enabled store'), and clarifies that it lists tools such as search, cart, and shipping. This distinguishes it from sibling search/detail/list tools in general, though it does not explicitly name them.
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 gives an explicit usage context: 'Use this to understand what a store supports before shopping.' This implies discovery is a prerequisite to shopping, but it does not mention alternatives or when not to use it, so the guidance is clear but not exhaustive.
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 resource or action: domain status, store capabilities, product variants, categories, store listings, aggregate search, single-store search, and policies. The only similar pair, search-all and search-catalog, is clearly differentiated by scope in their descriptions.
All tool names follow the same lowercase hyphenated verb_noun pattern, such as check-domain, list-stores, and search-catalog. Verbs are consistently placed first and accurately describe each action.
Eight tools is well within the ideal range, and each tool serves a distinct step in the UCP discovery and shopping workflow. There are no redundant or extraneous tools.
The set covers UCP checking, store and category discovery, single-store and multi-store product search, product details, and policy lookup. Direct cart or checkout operations are absent, but discover-store can reveal such capabilities, making the core discovery workflow reasonably complete.