EPA Air Quality System (AQS) MCP Server

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

With no annotations provided, the description carries the full burden. It discloses key behavioral traits: it's a read operation ('Get'), requires authentication (implied by email/key parameters), returns potentially large data volumes ('This can return large amounts of data'), and provides data format details (arithmetic mean, maximum values, etc.). It doesn't mention rate limits, pagination, or error handling, but covers the essential behavior well for a data retrieval tool.

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 efficiently structured in three sentences: purpose statement, data content details, and important notes about requirements and data volume. Every sentence adds value without redundancy. It's appropriately sized and front-loaded with the core purpose.

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 data retrieval tool with 6 parameters (4 required), 100% schema coverage, but no annotations or output schema, the description provides good contextual completeness. It covers what the tool does, what data it returns, authentication requirements, and data volume considerations. The main gap is lack of output format details, but given the complexity level and schema coverage, this is a minor omission.

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%, providing detailed documentation for all 6 parameters. The description adds minimal parameter semantics beyond the schema, only explicitly mentioning the state FIPS code requirement. It doesn't explain relationships between parameters or provide additional context about their usage. The baseline of 3 is appropriate when the schema does the heavy lifting.

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 clearly states the specific action ('Get daily summary air quality data'), resource ('for all monitoring sites in a state'), and scope ('Daily summaries include arithmetic mean, maximum values, observation counts, and AQI values for each day'). It distinguishes from siblings by specifying 'daily' (vs annual/quarterly) and 'by state' (vs by box/cbsa/county/site).

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?

The description provides clear context for when to use this tool ('Get daily summary air quality data for all monitoring sites in a state') and mentions a constraint ('Requires state FIPS code'). It doesn't explicitly state when not to use it or name specific alternatives among the many sibling tools, though the 'daily' and 'by state' aspects implicitly differentiate it from annual/quarterly summaries and other geographic scopes.

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