Swissgroceries MCP
Swissgroceries MCP lets an MCP client search Swiss grocery products, compare prices and deals across chains, find stores and stock, and plan multi-store shopping trips.
Search products across Migros, Coop, Aldi, Denner, Lidl, Volgshop, Otto's, and opt-in Coop City with price, size, tag, chain, pagination, and store filters.
Get full product details by chain and product ID, including price, unit price, tags, category, image, and active promotions.
Find grocery stores near a Swiss ZIP, GPS coordinates, or free-text address, filtered by chain and radius.
List current promotions filterable by chain, keyword, store ID, and days until expiry.
Check which stores of a supported chain have a specific product in stock, optionally near a location or for one store ID.
Plan shopping trips for item lists using single_store, split_cart, or absolute_cheapest strategies, with quantities, preferred or pinned products, and split-trip penalties.
Run health_check to probe chain adapters for status, latency, and capabilities.
Use MCP prompts and resources for weekly deals digests, basket comparisons, cheapest recipe ingredients, and chain capability discovery.
Real-time Swiss grocery shopping over the Model Context Protocol. Search products, compare prices across Migros, Coop, Aldi, Denner, Lidl, Volgshop, Otto's, and Coop City, see weekly promotions, and plan multi-store shopping trips. Works with any MCP-compatible client (Claude Desktop, Claude Code, Cursor, Cline, Continue, VS Code MCP extensions, custom clients).
Disclaimer
This is a personal fun project. It is not affiliated with, endorsed by, or sponsored by Migros, Coop, Aldi, Denner, Lidl, Volg, Otto's, or any other retailer. It uses publicly accessible mobile-app endpoints to make Swiss grocery shopping a bit smarter for end users.
If you represent any of these stores and have concerns (about API usage, branding, scraping rate, or anything else), please reach out to the maintainer through GitHub and we will work it out. No need to escalate.
API stability: the chain APIs used here are unofficial and can change at any time. The maintainer is not responsible for failures caused by upstream changes; please open an issue with the response sample so the affected adapter can be updated.
PRs welcome. New chains, better matchers, smarter strategies, bug fixes, doc improvements; all encouraged. See CONTRIBUTING.md.
Install
No accounts, no tokens, no API keys required. The Denner adapter self-registers an anonymous client on first use; everything else uses public endpoints.
Claude Desktop (one-click)
Download swissgroceries-mcp.mcpb from the Releases page and:
macOS: double-click or drag onto the Claude Desktop app icon.
Windows: Settings → Extensions → Advanced → Install Extension → select the file.
Claude Code (one-liner)
claude mcp add swissgroceries -- npx -y @nicktcode/swissgroceries-mcpCursor / Cline / Continue / VS Code / Claude Desktop (manual config)
Most MCP-compatible clients accept the same JSON server entry. Add it to your client's MCP config file (paths vary, see your client's docs):
{
"mcpServers": {
"swissgroceries": {
"command": "npx",
"args": ["-y", "@nicktcode/swissgroceries-mcp"]
}
}
}Common config paths:
Claude Desktop:
~/Library/Application Support/Claude/claude_desktop_config.json(macOS),%APPDATA%\Claude\claude_desktop_config.json(Windows).Cursor:
.cursor/mcp.jsonin the project, or~/.cursor/mcp.jsonglobally.Cline / Continue / VS Code: see each client's MCP documentation.
Custom clients: any stdio-based MCP client can spawn
npx -y @nicktcode/swissgroceries-mcpdirectly.
Related MCP server: trundler
What you can ask
Price comparison
"Where is milk cheapest near 8001 Zürich right now?"
"Compare pasta prices across Migros and Coop."
"Show me organic milk options under CHF 3."
Shopping planning
"I need milk, bread, eggs, chicken, and pasta near 8050. Where should I shop to keep costs down?"
"Plan my weekly shop for 5 items near 4052 Basel, one stop only."
"Split my cart across stores for the absolute lowest total, but add a 2 CHF penalty per extra trip."
Promotions and deals
"What is on sale at Aldi this week?"
"Any Migros deals on cheese ending this week?"
"Show me all promotions across chains for pasta."
Stores and stock
"Find Coop stores within 3 km of Bern Hauptbahnhof."
"Which Migros near me has product 4389992 in stock?"
"List Denner branches near 8050."
Tools
Tool | What it does |
| Find grocery stores near a location, filtered by chain and radius. |
| Cross-chain product search with normalised price, unit price, size, and tags. |
| Full product details for a chain plus product ID pair. |
| Current promotional deals, filterable by chain, keyword, store, or expiry. |
| Stores of a chain that have a given product in stock. |
| Plan a multi-store trip for a shopping list near a location. |
| Probe each registered chain adapter and report status, latency, and capabilities. |
Each tool exposes rich JSON Schema with field-level descriptions, so the LLM knows when and how to call it.
Prompts
Prompt | What it does |
| Summarise this week's best grocery deals across the configured chains. Optional category, chains, and location filters. |
| Compare a shopping basket across all chains and recommend single-store vs split-cart strategies. |
| From an ingredient list (or recipe URL) find the cheapest place to buy each item and produce a consolidated shopping plan. |
Prompts are surfaced as one-click templates in MCP-aware clients (Claude Desktop, Cursor, Cline). They produce structured user messages that drive the right tool calls — useful as a starting point and as discovery of what the server can do.
Resources
URI | Content |
| JSON list of registered chain adapters and their capabilities ( |
Chain coverage
Chain | Product search | Promotions | Per-store stock | Nutrition | Auth |
Migros | Full catalog | Yes | Yes | Yes (product detail) | Guest token (auto, rotated on expiry) |
Coop | coop.ch catalog (coopathome) | Yes | Yes (geo) | Yes (product detail) | None |
Aldi | Full catalog | Yes | No | No (API exposes only allergen claims) | None |
Denner | Full catalog | Yes | No | No | Anonymous self-auth (signup + signin, rotated) |
Lidl | Online assortment via the lidl.ch storefront (current + upcoming weekly offers, ~600 items; food only, de/fr/it) | Yes (weekly leaflet) | No | No | None |
Volgshop | Full catalog | Yes ( | No (delivery-only) | Yes (parsed from free-text attribute, basis assumed 100g) | None |
Otto's | Grocery-adjacent (food, drugstore, baby) | Yes (priceLabels facet) | Yes (per-store stockLevel) | No | None |
Coop City | Department-store catalog (coop-city.ch: cosmetics, household, fashion, electronics). Opt-in: only queried when | Yes ( | Yes (per-store stockLevel, capped at 50) | No | None |
NormalizedProduct.nutrition is normalized to a per-100g (or per-100ml) basis with the standard Swiss labelling fields — energyKj, energyKcal, fat, saturatedFat, carbs, sugar, fiber, protein, salt — so consumers can sort across chains ("highest protein per 100g lasagne") even though each upstream API exposes the data on a different surface and in a different shape. Missing or unparseable fields are left undefined; adapters never fabricate values.
Configuration
Env var | Default | Effect |
| (unset) | Optional pre-supplied Denner Bearer JWT. Without it, the adapter self-registers anonymously on first use and rotates the token automatically. |
|
| Default Lidl store ID used when no |
| (default iOS Safari UA) | Override the User-Agent for Coop calls if DataDome ever blocks the default. |
|
|
|
| (unset) | Set to |
How it works
Each grocery chain is wrapped in an independent adapter (src/adapters/<chain>/) that handles authentication, HTTP calls, and raw-to-normalised mapping. Adapters all produce the same NormalizedProduct, NormalizedStore, and NormalizedPromotion shapes (defined in src/adapters/types.ts), so the rest of the system never has to know which chain it is talking to.
The HTTP utility (src/util/http.ts) underpins every adapter except Migros (which delegates to the migros-api-wrapper library): in-memory response caching with a 5-minute TTL, retry with exponential backoff (3 attempts, 250 ms base), per-host rate limiting (~10 requests per second), and a per-host circuit breaker that opens after 5 consecutive failures and resets after 60 seconds.
The shopping planner (src/services/planner.ts) fans out store and product searches in parallel across all active adapters, then feeds results into a strategy solver (src/services/strategy.ts) that supports three modes:
single_store: minimise the number of stops.split_cart: cheapest split across chains, with a configurable per-stop penalty.absolute_cheapest: cheapest split, ignoring stop count.
Cross-chain comparisons are kept fair by a category-text canonicality filter (src/services/matcher.ts, isCanonical). When at least one chain returns a product whose category text matches the query, results from chains that only returned tangential products (for example, Apfelschorle when searching for "apfel") are dropped from the comparison matrix for that item.
MCP client (any LLM)
│
│ MCP tool call
▼
src/index.ts ── buildRegistry() ────────────────────────────────────────┐
│ │
│ routes to tool handler │
▼ ▼
src/tools/ src/adapters/
find_stores.ts ──► geocoding ──► adapter.searchStores migros/
search_products.ts ──────────────► adapter.searchProducts coop/
get_product.ts ──────────────► adapter.getProduct aldi/
get_promotions.ts ──────────────► adapter.getPromotions denner/ (auto-auth)
find_stock.ts ──────────────► adapter.findStoresWithStock lidl/
plan_shopping.ts ──► geocoding ──► planner ──► strategy solver
│
NormalizedProduct
NormalizedStore
NormalizedPromotionBuild from source
node --version # requires Node.js >=20
git clone https://github.com/nicktcode/swissgroceries-mcp
cd swissgroceries-mcp
npm install
npm run buildTo also build the .mcpb bundle locally:
npx tsx scripts/build-mcpb.tsTroubleshooting
Coop "DataDome challenge" error
You hit Coop's bot protection. Set SWISSGROCERIES_USER_AGENT_COOP to a freshly captured iOS Safari User-Agent string and try again.
Denner "auth_expired" error
Rare, since the adapter rotates its token automatically. If it persists, unset any custom DENNER_JWT and let the adapter re-bootstrap from scratch.
Lidl returns 0 results
Lidl Switzerland has no online grocery shop; lidl.ch only lists the current and upcoming weekly offers (around 600 items, food and non-food). Search covers that assortment, so a product that isn't on offer this or next week returns 0 results. This is expected.
ZIP unknown error
The static lookup table covers all 3,190 official Swiss postcodes. If yours is missing, pass { lat, lng } directly or open an issue with the missing PLZ.
Migros stores nowhere near my location
The Migros store-search API caps at ~10 results per query. The adapter passes a city hint derived from your ZIP. If you call the adapter directly without ZIP-based geocoding, pass cityHint explicitly.
Development
npm test # full test suite, no network calls
RUN_LIVE=1 npm test # also runs live smoke tests against real chain APIs
npm run dev # tsx watcher for local iteration
SWISSGROCERIES_DISABLE_CACHE=1 RUN_LIVE=1 npm test # cache off, useful for debugging
SWISSGROCERIES_LOG_LEVEL=debug npm run dev # verbose loggingThe test suite uses Vitest. Fixture JSON files live under tests/fixtures/<chain>/. Capture scripts in scripts/ show how to refresh them.
Adding a new chain
See CONTRIBUTING.md for the full guide. Quick version:
Capture API responses with Charles Proxy or mitmproxy on the chain's iOS or Android app.
Create
src/adapters/<chain>/{client,tags,normalize,index}.tsfollowing the existing patterns. Usesrc/adapters/aldi/as the simplest reference.Map raw responses to
NormalizedProduct,NormalizedStore, andNormalizedPromotion.Declare capability flags accurately.
Register the adapter in
src/index.ts'sbuildRegistry().Add fixture-based tests under
tests/adapters/.
License
PolyForm Shield 1.0.0 from v0.10.0. You can use and modify it for
anything that doesn't compete with this software or the author's own products
built on it (Swiss grocery search, price comparison and shopping apps or
services), even if your product is free. Personal use in your own MCP client is
fine. See LICENSING.md or contact nick@thommen.it.
v0.7.5 to v0.9.0 were released under AGPL-3.0-only and v0.7.4 and earlier under MIT; those published versions keep their original licenses.
Available Tools
7 toolsfind_stockA
Check which stores of a given chain have a specific product in stock. Optionally filter by proximity to GPS coordinates or query a single store by ID. Not all chains support per-store stock queries; unsupported chains return a clear error. Use for "is this product available near Zurich HB?", "which Coop has item X in stock?".
| Name | Required | Description | Default |
|---|---|---|---|
| near | No | Optional location to filter nearby stores. Pass coordinates, a Swiss ZIP, or a free-text address. If omitted, all stores may be queried. | |
| chain | Yes | The chain to query for stock. Only chains with perStoreStock capability are supported. | |
| storeId | No | Query a single specific store by its chain-specific store ID. Takes precedence over `near`. | |
| productId | Yes | Chain-specific product ID to check stock for. Obtain via search_products or get_product. |
TDQS
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the burden and does disclose a key behavioral trait: not all chains support per-store stock queries and unsupported chains return a clear error — a failure mode the agent needs before calling. It does not cover return shape (whether the result is stores with boolean stock or counts) or any rate/permission concerns, keeping it below a 5.
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?
Three sentences plus two example phrases, with the core capability front-loaded and the unsupported-chain caveat before the illustrative queries. No sentence is redundant.
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 four-parameter read tool with no output schema and no annotations, the description covers purpose, filtering options, and the unsupported-chain error path. The one gap is that it does not say what the response contains (per-store availability flags versus summaries), which would help the agent interpret results.
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 chain, productId, near variants, and storeId precedence are all fully documented in the schema. The description only restates that proximity filtering is optional and a single store can be queried by ID, adding no syntax or constraint detail beyond the structured fields — baseline 3.
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?
States a specific verb and resource — checking which stores of a given chain have a specific product in stock — and the examples anchor it to a concrete question shape. It is clearly distinguishable from find_stores (store listing) and search_products (product lookup) because the output is a stock-availability intersection of the two.
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?
Gives concrete usage contexts ("is this product available near Zurich HB?", "which Coop has item X in stock?") and explains the optional proximity filter versus the single-store-by-ID path. It stops short of explicitly routing away from siblings (e.g. "use find_stores to list branches without stock data"), so it 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.
find_storesA
Find grocery stores near a location, filtered by chain and search radius. Accepts a Swiss ZIP code, GPS coordinates, or a free-text address as the search center. Returns store name, address, chain, location, and opening hours where available. Use for "find a Migros near me", "which Coop branches are in 8001?", or before checking stock.
| Name | Required | Description | Default |
|---|---|---|---|
| near | Yes | Center of the search radius. Pass either coordinates, a Swiss ZIP, or a free-text address. | |
| chains | No | Limit results to specific chains. Omit to search all configured chains. Coop City (coopcity) is opt-in and only included when listed here. | |
| radiusKm | No | Search radius in kilometers (1–50). Defaults to 5 km. |
TDQS
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are supplied, so the description carries the full behavioral burden. It does disclose the returned fields and a data-availability caveat ("opening hours where available"); however, it says nothing about result limits, pagination, behavior when geocoding fails, or rate constraints from the Nominatim dependency for a lookup that is clearly a read operation.
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?
Four tight sentences, front-loaded with purpose, then inputs, then outputs, then usage examples. Every sentence contributes information an agent needs and there is no filler or repetition of the tool name.
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?
With three parameters, full schema coverage, no output schema, and no annotations, this description does the right amount of work: it explains the accepted input modes and enumerates return fields since no output schema exists. The remaining gap is failure and limit behavior, which an agent would want for a search that can silently return empty results.
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 all three parameters including the anyOf location forms and the Nominatim note. The description restates the accepted input modes and the chain/radius filters but adds no format, precedence, or behavior detail beyond what the schema says — 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?
States a specific verb and resource ("Find grocery stores near a location") plus the two filters (chain, radius), which is enough to distinguish it from search_products, find_stock, and get_promotions without opening a schema. The scope is explicit and there is no ambiguity about what the tool returns.
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?
Provides concrete invocation examples ("find a Migros near me", "which Coop branches are in 8001?") and a sequencing hint — "before checking stock" — which implicitly routes to find_stock. It stops short of naming the alternative tool explicitly or stating when not to use it (e.g. when you already have a store ID).
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
get_productA
Fetch full product details for a specific chain + product ID pair. Returns { product, fetchedAt, fromCache }: the product carries price, brand, size, unit price, tags, category, image URL, and active promotions, while fetchedAt + fromCache report how fresh the data is. Obtain product IDs from search_products. Useful for drilling into a search result. Use for "get details for this Migros product" or "what is the unit price of this item?".
| Name | Required | Description | Default |
|---|---|---|---|
| id | Yes | Chain-specific product identifier, e.g. Migros cumulus ID or Coop product number. Obtain via search_products. | |
| chain | Yes | The grocery chain that owns this product ID. |
TDQS
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden and does meaningful work: it discloses that responses include a cached-data signal (fromCache) and a timestamp (fetchedAt), which tells the agent data may be stale. It does not state behavior for unknown/invalid product IDs or any auth/rate constraints, leaving one real gap.
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?
Purpose comes first, then return shape, then how to get IDs, then example phrasings — a sensible front-loaded order. Slightly padded by the enumerated field list and two example utterances, but nothing is genuinely wasteful.
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 correctly compensates by naming the top-level response fields and the product payload. For a simple two-parameter lookup this is nearly complete; only error/miss behavior is unaddressed.
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% and both parameters are already documented with the chain enumeration and ID provenance, so the schema does the heavy lifting. The description reinforces the pairing constraint (ID is chain-specific) but adds no format or validation detail beyond that. 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?
Opens with a specific verb and resource ("Fetch full product details for a specific chain + product ID pair"), which immediately separates it from the listing-style sibling search_products. The scope is unambiguous: one chain/product pair, full detail rather than search results.
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?
Explicitly routes the agent through search_products to obtain IDs and frames the tool as the drill-down step after a search, with two concrete example utterances. It stops short of stating exclusions (e.g., don't use this to browse or to look up stores), but the sequencing guidance is clear.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
get_promotionsA
List current promotional deals across configured Swiss grocery chains. Filter by chain, keyword, store ID, or how many days until the promotion expires. Returns promotion name, discount, validity dates, and applicable stores. Use for "what is on sale this week?", "any Migros deals on cheese?", or "promotions ending today".
| Name | Required | Description | Default |
|---|---|---|---|
| query | No | Optional keyword to filter promotions by product name, e.g. "Käse", "wine". | |
| chains | No | Limit to specific chains. Omit to fetch promotions from all configured chains. Coop City (coopcity) is opt-in and only included when listed here. | |
| storeIds | No | Restrict to promotions valid at these store IDs (chain-specific). Obtain store IDs from find_stores. | |
| endingWithinDays | No | Only return promotions ending within this many days (1–60). Useful for "ending soon" queries. |
TDQS
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full behavioral burden. 'List' clearly implies a read-only operation and the description discloses the returned fields, but it says nothing about result volumes, pagination, whether 'current' means strictly active-now, or freshness/caching of the aggregated chain data. That is a real gap for a multi-source scraper-style tool, though the core read-only nature is clear.
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?
Three sentences: purpose, filter dimensions, return shape, then example queries. The purpose is front-loaded and every clause adds routing or selection value; nothing is redundant 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?
For a read-only, four-optional-parameter lookup with no output schema, the description covers purpose, filters, and return fields, which is most of what an agent needs. It stops short of describing result-set size or ordering behavior, which would matter when combining with plan_shopping or search_products.
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 all four parameters (query, chains, storeIds, endingWithinDays) are already documented in the schema, including the coopcity opt-in nuance and the find_stores pointer. The description restates the filter dimensions in its own words but adds no format or semantic detail beyond the schema, so 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?
The description opens with a specific verb+resource+scope: 'List current promotional deals across configured Swiss grocery chains.' It also states the return fields (name, discount, validity dates, stores), so an agent knows exactly what the tool produces. No sibling tool overlaps with promotions, so no differentiation is needed.
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?
Three concrete example queries ('what is on sale this week?', 'any Migros deals on cheese?', 'promotions ending today') make the intended use cases unambiguous. It lacks explicit when-not guidance or direction to an alternative tool for non-promotion queries, but the positive routing signal is strong.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
health_checkA
Probe each registered chain adapter with a trivial query and report status, latency, and capability flags. Use this when a chain seems missing from results or when debugging adapter problems.
| Name | Required | Description | Default |
|---|---|---|---|
| chains | No | Chains to probe. Default: all configured. | |
| timeoutMs | No | Per-chain timeout in milliseconds. Default 5000. |
TDQS
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the burden. It discloses that probing uses a trivial query and reports status/latency/flags, plus timeout defaults, but omits whether the operation is read-only/non-destructive, any auth or cost implications, and how many adapters are hit by default.
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?
Two sentences, front-loaded with what it does followed by when to use it. No wasted words.
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 no-annotation, no-output-schema diagnostic tool, the description compensates by describing the return payload (status, latency, capability flags) and the triggering scenarios. Minor gap is the lack of explicit safety/non-destructive confirmation.
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 both parameters (chains, timeoutMs) are already well documented with defaults and bounds. The description adds no meaning beyond the schema, so 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?
States a specific verb (probe) and resource (registered chain adapters) and enumerates the reported outputs (status, latency, capability flags). This clearly separates it from data-fetching siblings like find_stores and search_products, though it doesn't name them explicitly.
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?
Gives concrete triggering conditions: 'when a chain seems missing from results' or 'when debugging adapter problems.' Clear context, but doesn't explicitly name the alternative data tools or state when NOT to use it.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
plan_shoppingA
Plan a multi-store shopping trip near a location, picking the best products across configured Swiss grocery chains. Items can be generic ("milch", "pasta") or pinned to a specific SKU. Returns a primary plan plus alternatives. Use when the user gives a list of items and asks "where should I shop?" or "what's cheapest?". Strategies: single_store (one chain), split_cart (multi-chain with stop penalty), absolute_cheapest (no penalty).
| Name | Required | Description | Default |
|---|---|---|---|
| near | Yes | Shopper's location — used to find nearby stores. Pass coordinates, ZIP, or address. | |
| items | Yes | The list of items to shop for. At least one item required. | |
| chains | No | Restrict the plan to these chains. Omit to consider all configured chains. Coop City (coopcity) is opt-in and only included when listed here. | |
| radiusKm | No | Only consider stores within this radius of the provided location (1–50 km). Default 5 km. | |
| strategy | Yes | single_store: buy everything at one chain (minimises trips). split_cart: allow multiple chains but add splitPenaltyChf per extra stop. absolute_cheapest: pick the cheapest source per item regardless of stops. | |
| splitPenaltyChf | No | Cost in CHF added per extra store stop in split_cart strategy. Default 2.00. |
TDQS
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden. It discloses the return shape (primary plan plus alternatives), that items can be generic or SKU-pinned, and how each strategy trades off stops versus cost. It doesn't state that no purchase is made or how expensive the search is, but for a read-only planner the disclosure is solid.
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 purpose and triggering scenarios are front-loaded, followed by the strategy distinctions, with no filler. Every sentence adds either selection guidance or behavioral context.
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 six-parameter planner with no output schema, the description says a primary plan and alternatives are returned but not what those contain (prices, per-store breakdowns, cost estimates). The parameter side is covered by the rich schema, but the return-value side is thin for a tool of this complexity.
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 every parameter in depth. The description adds little beyond what is in the schema – it restates that items may be generic or pinned and repeats the strategy meanings already given in the enum description. Baseline 3 is correct.
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 and resource – "Plan a multi-store shopping trip near a location, picking the best products across configured Swiss grocery chains" – which is clearly distinct from sibling tools like search_products or find_stores. An agent can tell this is the multi-store optimizer, not a single-product search or store lookup.
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 explicitly states the triggering scenario (a list of items plus "where should I shop?" or "what's cheapest?") and explains the three strategies. It does not explicitly name which sibling to use instead for a single product lookup, but the context is clear enough to route correctly.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
search_productsA
Search for products across configured Swiss grocery chains (Migros, Coop, Aldi, Denner, Lidl, Volgshop, Otto's, Coop City) by keyword. The coop chain covers the coop.ch supermarket assortment (groceries, household, drugstore) only. The Coop City department-store range (coop-city.ch: cosmetics, fashion, household, electronics) is the separate coopcity chain, which is opt-in: include it in chains to search it (it is skipped when chains is omitted). Supports optional filters for price, size range, and product tags (organic, vegan, budget, etc.). Returns results grouped by chain with normalised price, unit price, size, and promotion info. A sources map reports each chain's data freshness (fetchedAt timestamp + fromCache flag) so you can tell the user how current the prices are. Every queried chain has a key in byChain; when a chain fails (e.g. bot protection or an outage) its array is empty and errors lists the chain with a code and reason, so check errors before telling the user a chain has no results. Use for "find organic milk under 2 CHF", "compare pasta prices", or "search for gluten-free bread".
| Name | Required | Description | Default |
|---|---|---|---|
| limit | No | Maximum number of results per chain (1–50). Defaults to chain-specific limit. | |
| query | Yes | Search term in any language, e.g. "Milch", "pâtes", "Bier". At least 1 character. | |
| chains | No | Restrict search to specific chains. Omit to search all configured chains in parallel. Coop City (coopcity) is opt-in and only included when listed here. | |
| offset | No | Skip the first N results per chain. Use with `limit` to paginate. Default 0. | |
| filters | No | Optional product filters applied after search. | |
| storeIds | No | Filter results to products available in these store IDs (chain-specific internal IDs). |
TDQS
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden and does so: it discloses parallel fan-out across chains, opt-in membership for one chain, grouped-by-chain return shape, per-chain freshness metadata via `sources`, and failure semantics (empty array + `errors` with code/reason on bot protection or outage). That is far beyond what a bare 'search' label would convey.
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?
Core scope and the coop/coopcity distinction are front-loaded, and the examples land at the end as intended. It runs long with several sentences, and the coopcity opt-in rule is stated twice (once outright, once parenthetically), which is mild redundancy rather than waste.
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?
There is no output schema, and the description compensates by characterizing the return shape (`byChain`, normalised price/unit price/size/promotion, `sources` freshness, `errors`). For a 6-parameter nested-filter search tool, nothing an agent needs to call it or interpret results 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 baseline is 3; the description adds real meaning on top by explaining that omitting `chains` searches everything except coopcity, and by characterizing the filter axes (price, size range, tags) that the schema enumerates. It does not add syntax or interaction notes for `limit`/`offset` pagination beyond what the schema documents.
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?
States a specific verb and resource ('search for products') plus the exact scope (eight named Swiss grocery chains), and explicitly disambiguates the `coop` vs `coopcity` assortments. An agent can distinguish this from get_product or find_stock without opening any schema.
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?
Gives concrete invocation triggers ('find organic milk under 2 CHF', 'compare pasta prices', 'gluten-free bread') and a conditional rule for the opt-in `coopcity` chain. It also instructs the agent to check `errors` before reporting an empty chain, which is a genuine when-to-use-this-and-how caveat.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Tool Schema Changelog
Recent tool additions, removals, and schema changes observed during successful MCP inspections.
7 tool updates
v0.12.0- Changed
find_stock1 field changed- changed
Input schema / properties / chain / enumPrevious value: -[ - "migros", - "coop", - "aldi", - "denner", - "lidl", - "farmy", - "volgshop", - "ottos", - "coopcity" -]New value: +[ + "migros", + "coop", + "aldi", + "denner", + "lidl", + "volgshop", + "ottos", + "coopcity" +]
- Changed
find_stores1 field changed- changed
Input schema / properties / chains / items / enumPrevious value: -[ - "migros", - "coop", - "aldi", - "denner", - "lidl", - "farmy", - "volgshop", - "ottos", - "coopcity" -]New value: +[ + "migros", + "coop", + "aldi", + "denner", + "lidl", + "volgshop", + "ottos", + "coopcity" +]
- Changed
get_product1 field changed- changed
Input schema / properties / chain / enumPrevious value: -[ - "migros", - "coop", - "aldi", - "denner", - "lidl", - "farmy", - "volgshop", - "ottos", - "coopcity" -]New value: +[ + "migros", + "coop", + "aldi", + "denner", + "lidl", + "volgshop", + "ottos", + "coopcity" +]
- Changed
get_promotions1 field changed- changed
Input schema / properties / chains / items / enumPrevious value: -[ - "migros", - "coop", - "aldi", - "denner", - "lidl", - "farmy", - "volgshop", - "ottos", - "coopcity" -]New value: +[ + "migros", + "coop", + "aldi", + "denner", + "lidl", + "volgshop", + "ottos", + "coopcity" +]
- Changed
health_check1 field changed- changed
Input schema / properties / chains / items / enumPrevious value: -[ - "migros", - "coop", - "aldi", - "denner", - "lidl", - "farmy", - "volgshop", - "ottos", - "coopcity" -]New value: +[ + "migros", + "coop", + "aldi", + "denner", + "lidl", + "volgshop", + "ottos", + "coopcity" +]
- Changed
plan_shopping3 fields changed- changed
Input schema / properties / chains / items / enumPrevious value: -[ - "migros", - "coop", - "aldi", - "denner", - "lidl", - "farmy", - "volgshop", - "ottos", - "coopcity" -]New value: +[ + "migros", + "coop", + "aldi", + "denner", + "lidl", + "volgshop", + "ottos", + "coopcity" +] - changed
Input schema / properties / items / items / properties / preferredChain / enumPrevious value: -[ - "migros", - "coop", - "aldi", - "denner", - "lidl", - "farmy", - "volgshop", - "ottos", - "coopcity" -]New value: +[ + "migros", + "coop", + "aldi", + "denner", + "lidl", + "volgshop", + "ottos", + "coopcity" +] - changed
Input schema / properties / items / items / properties / preferredProductId / properties / chain / enumPrevious value: -[ - "migros", - "coop", - "aldi", - "denner", - "lidl", - "farmy", - "volgshop", - "ottos", - "coopcity" -]New value: +[ + "migros", + "coop", + "aldi", + "denner", + "lidl", + "volgshop", + "ottos", + "coopcity" +]
- Changed
search_products1 field changed- changed
Input schema / properties / chains / items / enumPrevious value: -[ - "migros", - "coop", - "aldi", - "denner", - "lidl", - "farmy", - "volgshop", - "ottos", - "coopcity" -]New value: +[ + "migros", + "coop", + "aldi", + "denner", + "lidl", + "volgshop", + "ottos", + "coopcity" +]
7 tool updates
v0.11.0- Changed
find_stock1 field changed- changed
Input schema / properties / chain / enumPrevious value: -[ - "migros", - "coop", - "aldi", - "denner", - "lidl", - "farmy", - "volgshop", - "ottos" -]New value: +[ + "migros", + "coop", + "aldi", + "denner", + "lidl", + "farmy", + "volgshop", + "ottos", + "coopcity" +]
- Changed
find_stores2 fields changed- changed
Input schema / properties / chains / descriptionPrevious value: -"Limit results to specific chains. Omit to search all configured chains."New value: +"Limit results to specific chains. Omit to search all configured chains. Coop City (coopcity) is opt-in and only included when listed here." - changed
Input schema / properties / chains / items / enumPrevious value: -[ - "migros", - "coop", - "aldi", - "denner", - "lidl", - "farmy", - "volgshop", - "ottos" -]New value: +[ + "migros", + "coop", + "aldi", + "denner", + "lidl", + "farmy", + "volgshop", + "ottos", + "coopcity" +]
- Changed
get_product1 field changed- changed
Input schema / properties / chain / enumPrevious value: -[ - "migros", - "coop", - "aldi", - "denner", - "lidl", - "farmy", - "volgshop", - "ottos" -]New value: +[ + "migros", + "coop", + "aldi", + "denner", + "lidl", + "farmy", + "volgshop", + "ottos", + "coopcity" +]
- Changed
get_promotions2 fields changed- changed
Input schema / properties / chains / descriptionPrevious value: -"Limit to specific chains. Omit to fetch promotions from all configured chains."New value: +"Limit to specific chains. Omit to fetch promotions from all configured chains. Coop City (coopcity) is opt-in and only included when listed here." - changed
Input schema / properties / chains / items / enumPrevious value: -[ - "migros", - "coop", - "aldi", - "denner", - "lidl", - "farmy", - "volgshop", - "ottos" -]New value: +[ + "migros", + "coop", + "aldi", + "denner", + "lidl", + "farmy", + "volgshop", + "ottos", + "coopcity" +]
- Changed
health_check1 field changed- changed
Input schema / properties / chains / items / enumPrevious value: -[ - "migros", - "coop", - "aldi", - "denner", - "lidl", - "farmy", - "volgshop", - "ottos" -]New value: +[ + "migros", + "coop", + "aldi", + "denner", + "lidl", + "farmy", + "volgshop", + "ottos", + "coopcity" +]
- Changed
plan_shopping4 fields changed- changed
Input schema / properties / chains / descriptionPrevious value: -"Restrict the plan to these chains. Omit to consider all configured chains."New value: +"Restrict the plan to these chains. Omit to consider all configured chains. Coop City (coopcity) is opt-in and only included when listed here." - changed
Input schema / properties / chains / items / enumPrevious value: -[ - "migros", - "coop", - "aldi", - "denner", - "lidl", - "farmy", - "volgshop", - "ottos" -]New value: +[ + "migros", + "coop", + "aldi", + "denner", + "lidl", + "farmy", + "volgshop", + "ottos", + "coopcity" +] - changed
Input schema / properties / items / items / properties / preferredChain / enumPrevious value: -[ - "migros", - "coop", - "aldi", - "denner", - "lidl", - "farmy", - "volgshop", - "ottos" -]New value: +[ + "migros", + "coop", + "aldi", + "denner", + "lidl", + "farmy", + "volgshop", + "ottos", + "coopcity" +] - changed
Input schema / properties / items / items / properties / preferredProductId / properties / chain / enumPrevious value: -[ - "migros", - "coop", - "aldi", - "denner", - "lidl", - "farmy", - "volgshop", - "ottos" -]New value: +[ + "migros", + "coop", + "aldi", + "denner", + "lidl", + "farmy", + "volgshop", + "ottos", + "coopcity" +]
- Changed
search_products2 fields changed- changed
Input schema / properties / chains / descriptionPrevious value: -"Restrict search to specific chains. Omit to search all configured chains in parallel."New value: +"Restrict search to specific chains. Omit to search all configured chains in parallel. Coop City (coopcity) is opt-in and only included when listed here." - changed
Input schema / properties / chains / items / enumPrevious value: -[ - "migros", - "coop", - "aldi", - "denner", - "lidl", - "farmy", - "volgshop", - "ottos" -]New value: +[ + "migros", + "coop", + "aldi", + "denner", + "lidl", + "farmy", + "volgshop", + "ottos", + "coopcity" +]
7 tool updates
v0.7.10- First observed
find_stock - First observed
find_stores - First observed
get_product - First observed
get_promotions - First observed
health_check - First observed
plan_shopping - First observed
search_products
TDQS
Scored across 7 tools
Each tool targets a clearly distinct user intent: store discovery, product search, product detail, promotions, per-store stock, adapter health, and trip planning. The only mild overlap is that search_products includes promotion info while get_promotions is dedicated to deals, but the tool descriptions make the boundary clear.
All names use clear snake_case and are readable, with paired patterns like find_stores/find_stock and get_product/get_promotions. However, verbs vary across find, search, get, plan, and health_check does not follow a verb_noun pattern, so it is mostly rather than fully consistent.
Seven tools is well-scoped for a Swiss grocery comparison and planning server. Each tool has a distinct role and none feels redundant or excessive.
The surface covers the full read-only shopping workflow: finding stores, searching and inspecting products, discovering promotions, checking stock, diagnosing chain issues, and planning multi-store trips. No obvious lifecycle gap exists for the stated grocery-assistant purpose.
Maintenance
Related MCP Connectors
Unlock the power of food transparency with our Open Food Facts MCP server. Easily look up any food
Live prices, deals & optimal multi-stop shopping routes for German grocery & drug stores.
Hosted MCP for e-commerce: live product catalog, stock, and pricing for AI agents.
Shopping infrastructure for AI agents: product search, category price overviews, price checks and seller vetting across US online retail, as structured facts over MCP.
Related MCP Servers
- AlicenseCqualityCmaintenanceA Model Context Protocol server enabling product searches across e-commerce platforms, price history tracking, and product specification-based searches using natural language prompts.287 PyPI19MIT
- AlicenseAqualityBmaintenanceA local MCP server for grocery shopping, enabling product search, specials, and browsing across NZ supermarkets, with cart and order history for Countdown/Woolworths via browser-assisted login.141MIT
- AlicenseNot gradedqualityCmaintenanceMCP server for Dutch supermarkets and drugstores, enabling product search, price comparison, promotions, shopping lists, meal planning, price alerts, and budget tracking via natural language.MIT
- AlicenseNot gradedqualityBmaintenanceMCP server that lets an LLM search and compare prices across four German hardware-store retailers (Hornbach, BAUHAUS, Globus, OBI), with store pickup availability for local branches.MIT