US Government Open Data MCP

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

Annotations provide readOnlyHint=true, and the description does not contradict this. It adds valuable context beyond annotations by specifying the data range ('since 1900'), listing the causes, and noting the dataset's extent ('120+ years of data'), which helps the agent understand the tool's scope and limitations.

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 into three sentences: the core purpose, the specific causes, and the use case with data extent. Each sentence adds essential information without redundancy, making it front-loaded and highly concise.

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 the tool's moderate complexity, rich annotations (readOnlyHint), and full schema coverage, the description is mostly complete. It covers purpose, causes, and data range but lacks output details (no output schema) and explicit usage comparisons with siblings, leaving minor gaps.

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?

The input schema has 100% description coverage, clearly documenting all parameters. The description adds minimal parameter semantics by listing the causes and implying date filtering, but it does not provide additional details beyond what the schema already covers, aligning with 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 specific action ('Get'), resource ('age-adjusted death rates for major causes'), and temporal scope ('since 1900'). It explicitly lists the five causes and emphasizes the long-term trend analysis capability with '120+ years of data,' making the purpose distinct and comprehensive.

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 for 'long-term trend analysis' but does not explicitly state when to use this tool versus alternatives like 'cdc_mortality_rates' or 'cdc_causes_of_death' among siblings. It provides a general context but lacks specific guidance on tool selection or exclusions.

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