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Get gas prices today

get_gas_prices
Read-onlyIdempotent

Fetch EIA weekly retail gasoline and diesel prices by US region, state, or city to compare current averages and track week-over-week, four-week, and year-ago changes.

Instructions

Latest EIA weekly average retail price per gallon (taxes included) of regular, midgrade or premium gasoline, all grades or diesel for the US, an EIA region, one of nine surveyed states, one of ten surveyed cities, or the region of any other state, read at call time from eia.gov: price, change from last week and four weeks ago, the price a year ago, the last six survey weeks and the next release date.

Input Schema

NameRequiredDescriptionDefault
areaNoUS, a state name or code ("Texas", "CA"), a city EIA prices ("Chicago", "NYC"), or an EIA region ("Midwest", "PADD 2"). Default US. A state EIA does not price is answered with its region.
gradeNoDefault regular.

Schema Changelog

Changes observed during successful MCP inspections.

  1. First observedv1.0.0

TDQS

A3.7/5.0
Behavior4/5

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

Annotations already establish read-only, idempotent, open-world behavior, and the description adds meaningful context beyond that: the source is eia.gov, values are read fresh at call time, prices are weekly averages with taxes included, and the exact return fields (change vs. last week/four weeks/year ago, six survey weeks, next release date) are disclosed despite there being no output schema.

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

Conciseness4/5

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

It front-loads the resource and scope with no filler, and every clause carries information. However, all of it is crammed into one very long run-on sentence, which hurts parseability for a reader skimming for a decision.

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 two-parameter read tool with no output schema, the description is unusually complete: it covers data source, freshness, scope of areas and grades, and the full shape of the response. The only real omission is any guidance tying it to its sibling tools.

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 coverage is 100%, so both parameters are already fully documented, including the area fallback rule. The description adds only incidental color (taxes included, nine surveyed states, ten surveyed cities) and otherwise restates the area and grade options the schema already carries.

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

Purpose4/5

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

The description names a specific verb+resource (retrieve the latest EIA weekly average retail gasoline price) and enumerates exactly what data points come back. It implicitly separates itself from compare_gas_prices and estimate_fill_up_cost by being the raw single-area lookup, but never names or contrasts them.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines3/5

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

Usage is only implied: an agent can infer this is the plain price lookup while the siblings handle comparisons and cost math. There is no explicit when-to-use, when-not-to-use, or alternative routing statement.

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