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Glama

Compare gas prices by place

compare_gas_prices
Read-onlyIdempotent

Rank states, cities, or regions by weekly EIA gasoline prices for a chosen grade, including the US average and low-to-high price range.

Instructions

Ranks the areas EIA prices (states, cities, regions) from cheapest to most expensive for a grade this week, with the US average, the cheapest and the most expensive area.

Input Schema

NameRequiredDescriptionDefault
gradeNoDefault regular.
groupNoWhich areas to rank. Default all.

Schema Changelog

Changes observed during successful MCP inspections.

  1. First observedv1.0.0

TDQS

A4/5.0
Behavior4/5

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

Annotations already cover read-only, open-world, idempotent, and non-destructive behavior. The description adds ranking direction, weekly temporal scope, and output highlights (US average, cheapest, most expensive area). It does not describe tie handling or response structure in more detail.

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?

The definition is a single front-loaded sentence with no filler. It puts the ranking action and scope first, followed by the included summary values.

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?

The tool is low complexity, annotations cover the safety profile, and the schema fully documents parameters. The description also summarizes key return content, though it leaves 'all_grades' behavior implicit and does not fully specify output shape.

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%, with enums and defaults documented for both parameters. The description links grade to 'this week' and maps areas to states/cities/regions, but it does not clarify ambiguous cases such as grade='all_grades'. Baseline 3 is appropriate when the schema already carries parameter meaning.

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?

The description uses a specific verb and resource: it ranks EIA area prices for a grade this week. It also names the scope (states, cities, regions) and headline outputs, making it easy to distinguish from get_gas_prices and estimate_fill_up_cost.

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?

The comparison purpose is implied by 'Ranks' and the cheapest-to-most-expensive ordering, but there is no explicit when-to-use guidance or routing to sibling tools. It also does not say when not to use this tool.

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