US Government Open Data MCP

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

With no annotations provided, the description carries full burden. It discloses required credentials (AQS_API_KEY, AQS_EMAIL) and return data types, which is helpful. However, it doesn't mention rate limits, error handling, pagination, or whether this is a read-only query (implied by 'Find' but not explicit). More behavioral context would improve transparency for an unannotated 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 appropriately concise with three sentences: purpose, parameters, and usage/credentials. Each sentence adds value, and it's front-loaded with the core function. It could be slightly more structured by separating parameter details into a bullet list, but overall it's efficient with no wasted text.

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?

Given no annotations, no output schema, and 5 parameters, the description provides basic purpose and credentials but lacks details on return format, error cases, or advanced usage. It's minimally viable for a query tool but incomplete for full agent understanding without output schema or behavioral annotations.

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 all parameters thoroughly. The description lists param codes with pollutant names, adding minimal value beyond the schema's param description. It doesn't explain interactions between parameters (e.g., state/county filtering) or date format nuances, so it meets the baseline for high schema coverage.

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 tool's purpose: 'Find air quality monitoring stations from EPA AQS' with specific return fields (locations, dates, types, agencies). It distinguishes from siblings by focusing on EPA AQS monitors, unlike other tools for BEA, BLS, etc. However, it doesn't explicitly differentiate from similar EPA tools like 'epa_aqs_daily' or 'epa_air_quality' in the sibling list.

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 implies usage context by listing parameter codes and stating it's 'Useful for finding what is being measured and where,' but lacks explicit when-to-use guidance versus alternatives. It mentions required credentials (AQS_API_KEY, AQS_EMAIL) as prerequisites, but doesn't specify when to choose this over other EPA tools or data sources.

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