ViaFrei

find_fuel_station

Read-onlyIdempotent

Find which filling station matches your needs near a place or coordinates — filter by fuel grade, brand, name, or opening hours, and sort by distance, price, or name.

Instructions

Finds filling stations around a place or coordinate under any combination of filters — grade, brand, name, open now, open at a time you name, open 24 h — sorted by distance, price or name. Use when the question is WHICH station: the closest diesel to a stop, an ARAL open tonight, what one forecourt sells. Do NOT use for the plain "where is fuel cheapest" question (call find_cheapest_fuel) or for charging an electric car (call find_charging_station). Every result carries the attribution and the MTS-K note, and says how old each price and opening-hours claim is.

Input Schema

TableJSON Schema

Name	Required	Description	Default
`lat`	No	Latitude in WGS 84, e.g. 48.137. Use with lon when the caller already holds coordinates; otherwise use place.
`lon`	No	Longitude in WGS 84, e.g. 11.576. Use with lat; otherwise use place.
`fuel`	No	Only stations with a current price for this grade: "e5" (Super E5), "e10" (Super E10) or "diesel". Omit to get every station near the place whatever it sells — the answer then lists all the grades it holds a price for. Required when sort is "price", because a price ordering needs a grade.
`name`	No	Part of the station's own name or brand, case-insensitive: "Autohof", "Raststätte Fulda". Use it when the person named a specific forecourt rather than a chain. Combine with place to keep the search local.
`sort`	No	Order of the answer: "distance" (nearest first, the default — use it for "closest diesel to Hamburg Hbf"), "price" (cheapest first, needs fuel), or "name" (alphabetical, for a person scanning a list of a brand's forecourts).	distance
`brand`	No	Only stations of this brand, matched case-insensitively anywhere in the brand field: "ARAL", "Shell", "TotalEnergies", "JET". Use it when the person named a chain ("die ARAL an der B1"). Free stations often carry no brand at all and are then not matched by any brand.
`limit`	No	How many stations to return (1–10, default 5).
`place`	No	Where to look, as free text: a city ("München", "Munich"), a district or Kreis ("Kreis Fulda"), a Bundesland, a station or stop ("Hamburg Hbf"), a motorway ("A7"), or a street address with a house number ("Hauptstraße 12, 36037 Fulda"). Use this instead of coordinates whenever the person named a place. An address needs its town or postcode — a street and a number alone exist in many towns. Give either place OR lat+lon, never both.
`open_at`	No	Only stations open at that time in Germany (Europe/Berlin): "23:30" means the next time the clock shows 23:30, and "2026-09-30 06:15" a specific local date and time. Use it for "is it still open tonight". Do not pass it together with open_now — they ask the same question about two different clocks.
`language`	No	Set this on every call to the language the person is writing in: "en" if they wrote English, "de" if they wrote German. Do not leave it out because it has a default — the default is only the fallback when the language is genuinely unclear, and an English question answered in German is a wrong answer. Place names, station names and road numbers are never translated in either language; in English the German term is kept in parentheses so the person recognises it on signs and in local apps.	de
`open_now`	No	When true, only stations the published opening hours say are open at this moment. Default false. A station whose hours we have never read is NOT returned by this filter and is counted in the answer instead — the result never guesses that an unknown station is open.
`radius_km`	No	Search radius around the place in kilometres (1–25, default 5). 25 km is the provider's own ceiling — a larger circle is a dataset request, not a consumer question.
`whole_day`	No	When true, only stations the provider flags as open around the clock (24/7). Default false. Use it for a night drive; it is a stricter filter than open_now, which is satisfied by a station that closes at 22:00.

Schema Changelog

Changes observed during successful MCP inspections.

Changed3 schema fields changedv1.7.3Oct 5, 2026
- addedInput schema / properties / brand / maxLength
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Added value: +60
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- addedInput schema / properties / name / maxLength
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Added value: +120
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- addedInput schema / properties / place / maxLength
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Added value: +120
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Addedv1.4.8Oct 1, 2026

TDQS

A4.4/5.0

Behavior4/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint, idempotentHint, openWorldHint and destructiveHint=false, so the safety profile is covered. The description adds genuinely new behavioral context beyond that: results carry attribution and an MTS-K note and disclose the age/freshness of each price and opening-hours claim, which matters for a data-source-backed lookup. It stops short of describing pagination or result shape, but with annotations carrying safety this is strong.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

Front-loads purpose, then usage, then exclusions, then result behavior — a clean information hierarchy. Despite being three dense sentences it earns every clause, and the length is justified for a 13-parameter tool.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness4/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a 13-parameter, zero-required read tool with no output schema, the description covers routing, filtering axes and return-value provenance (attribution, MTS-K, staleness). It gives enough for correct invocation; only the detailed result shape is left implicit, which is a minor gap given the lack of an output schema.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

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 13 parameters in depth (including the place-XOR-lat/lon rule). The description's filter/sort enumeration largely restates what the schema provides, adding only natural-language framing rather than new semantics. Baseline 3 applies.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb ("Finds") and resource ("filling stations") with explicit scope ("around a place or coordinate") and summarizes the filter/sort axes. It also names the siblings it must not be confused with (find_cheapest_fuel, find_charging_station), so an agent can disambiguate 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.

Usage Guidelines5/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

Explicit when-to-use framing ("Use when the question is WHICH station") with concrete examples, plus explicit when-NOT-to-use guidance naming the correct alternative tool for each excluded case. This is the textbook routing pattern.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

find_fuel_station

Instructions

Input Schema

Schema Changelog

TDQS

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