US Government Open Data MCP

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It mentions the data source ('USGS monitoring sites') and real-time nature, but does not disclose critical traits such as rate limits, authentication needs, error handling, or whether the tool is read-only or has side effects. This leaves significant gaps for an agent to understand operational constraints.

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 sized and front-loaded, starting with the core purpose and key details (data types, station count, parameter codes) in the first sentence. Each subsequent sentence adds essential information without redundancy, making it efficient and easy to parse for an agent.

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 complexity of 6 parameters with no output schema and no annotations, the description is moderately complete. It covers the tool's purpose, data types, and query methods, but lacks details on output format, error cases, or behavioral constraints. This is adequate for basic use but leaves gaps for robust agent operation.

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 adds some value by explaining parameter codes (e.g., '00060=discharge (cfs)') and query methods, but does not provide additional semantics beyond what the schema offers, such as default behaviors or interdependencies between parameters like 'period' and 'start_dt'/'end_dt'.

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 with specific verbs ('Get real-time water data') and resources ('from USGS monitoring sites'), listing the types of data (streamflow, gage height, temperature) and the scale ('13,000+ stations nationwide'). It distinguishes itself from sibling tools like 'usgs_daily_water_data' and 'usgs_water_sites' by focusing on real-time data retrieval rather than daily summaries or site listings.

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 usage by detailing query methods ('by site ID, state, county, or hydrologic unit code (HUC)') and parameter codes, which helps guide when to use this tool. However, it does not explicitly state when not to use it or name alternatives (e.g., 'usgs_daily_water_data' for historical data), missing full explicit guidance.

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