US Government Open Data MCP

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

Annotations already declare readOnlyHint=true, so the agent knows this is a safe read operation. The description adds valuable context about the data source (CDC PLACES, BRFSS-based estimates) and return format (crude prevalence % by county), which isn't covered by annotations. However, it doesn't mention rate limits, authentication requirements, or data freshness.

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, comprehensive measure listing, and return format. Every sentence adds essential information with zero waste. The measure list is appropriately detailed for this data-rich tool.

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 read-only data retrieval tool with good annotations and full schema coverage, the description provides adequate context about data source, measures, and return format. The main gap is the lack of output schema, but the description compensates by specifying the return format. It could benefit from mentioning data years or update frequency.

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 fully documents all three parameters (state, measure, limit) with descriptions and constraints. The description adds marginal value by listing specific measure IDs beyond the schema's subset, but doesn't provide additional syntax, format, or semantic context beyond what's in the structured fields.

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 explicitly states the verb ('Get') and resource ('county-level health indicators from CDC PLACES') with specific scope (BRFSS-based estimates). It clearly distinguishes from sibling tools like 'cdc_places_city' by specifying county-level data, and from other CDC tools by focusing on health indicators rather than mortality, COVID, or other datasets.

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 (for county-level health indicators from CDC PLACES) and implicitly distinguishes it from city-level alternatives. However, it doesn't explicitly state when NOT to use it or name specific alternative tools for different geographic levels or data types beyond the sibling list.

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