MCP tools for product warranty lookup and claim windows — so shopping agents know coverage before a purchase.
Scored across 2 tools
The two tools have clearly distinct purposes: one performs a warranty lookup and mints a receipt, while the other retrieves an existing receipt by ID. An agent can easily tell which tool to use based on whether it has a warranty question or a receipt identifier.
Both names use snake_case with a verb_noun pattern: check_warranty and get_warranty_receipt. The convention is consistent and readable, though the second name is slightly more compound.
The server is intentionally narrow, but two tools is thin for a standalone warranty desk. The tools each earn their place, yet the surface feels borderline minimal rather than well-scoped.
For the stated purpose, the set covers warranty lookup, exclusions, claim location, optional purchase-date anchoring, and receipt retrieval. Minor gaps exist, such as listing or searching prior receipts, but core workflows are covered.
Look up a brand's standard manufacturer warranty for the US: coverage length (only when the brand's page states it), what it excludes, and where to claim. Optional purchase_date places the term on a calendar. Mints a public TRACE receipt. Not store return windows.
| Name | Required | Description | Default |
|---|---|---|---|
| as_of | No | YYYY-MM-DD; default today | |
| brand | Yes | Brand name, e.g. Apple, Samsung, Nike | |
| region | No | Only US in v0 | US |
| product | No | Free text product, e.g. iPhone 15 Pro | |
| category | No | Free text category, e.g. phone, tv, laptop | |
| purchase_date | No | YYYY-MM-DD |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the behavioral burden and discloses important limits ('only when the brand's page states it') plus a side effect ('Mints a public TRACE receipt'). It does not cover auth requirements, rate limits, or how to retrieve the receipt, so it is strong but not exhaustive.
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 three compact sentences with the core purpose front-loaded. Every sentence contributes useful scope, output, or side-effect information, and there is no filler.
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 six parameters, no annotations, and no output schema, the description does well by explaining the returned fields (coverage length, exclusions, claim location) and the receipt side effect. A small gap remains around how to use the sibling receipt tool and the role of product/category inputs.
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 schema already documents all six parameters. The description adds meaning for purchase_date by saying it places the term on a calendar, but it leaves as_of, product, and category to the schema and adds little beyond the parameter-level documentation.
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 and resource: looking up a brand's US manufacturer warranty, including coverage length, exclusions, and claim location. It distinguishes the tool from store return windows, but does not explicitly distinguish it from the sibling get_warranty_receipt.
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 when-not exclusion ('Not store return windows') and notes that purchase_date is optional for calendar placement. However, it does not name the sibling get_warranty_receipt or explain when to use that receipt-retrieval tool instead.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Fetch a public Warranty Desk TRACE receipt by id (wdr_...).
| Name | Required | Description | Default |
|---|---|---|---|
| id | Yes |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full behavioral burden, and 'public' is the one useful disclosure (no authentication needed). It says nothing about what happens when the id is unknown, whether the lookup is read-only/side-effect free, or what a returned receipt contains.
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 with zero filler, and the key qualifiers (public, by id, id format) come immediately. Brevity is efficient here rather than padded, though it borders on under-specification.
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?
This is a simple one-parameter lookup, but with no annotations and no output schema, the description should compensate for missing return-value and error semantics. Instead it stops at naming the resource, leaving the agent to guess what a receipt response looks like or what a failed lookup returns.
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 0% and the schema only types the id as a plain string, so the description's '(wdr_...)' prefix is genuinely additive format guidance. It still doesn't state requiredness or what the id identifies beyond the prefix convention.
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 gives a specific verb ('Fetch') and a clearly scoped resource ('a public Warranty Desk TRACE receipt'), plus the identifier form. It does not explicitly contrast with the sibling check_warranty, so the agent must infer the difference between fetching a receipt and checking warranty status.
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?
There is no statement of when to use this tool versus check_warranty, nor any prerequisite or exclusion. The only implied guidance comes from 'public ... by id', which hints at a lookup of an already-issued receipt but never says so.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Recent tool additions, removals, and schema changes observed during successful MCP inspections.
check_warrantyget_warranty_receipt
Add one secure layer between your agents and this server.