usgs_water_data

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

The annotation already indicates readOnlyHint=true. The description adds context about the scale (13,000+ stations) and the specific data types (discharge, gage height, temperature) with their parameter codes. This supplements the annotation by clarifying the scope and content of the read operation.

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 three sentences and front-loaded with purpose, then adds key context (station count, parameter codes, query methods). No redundant or unnecessary information. Highly efficient.

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 has 6 parameters with 100% schema coverage and no output schema, the description covers purpose, data types, scale, and query options. It could be improved by briefly describing the response format (e.g., JSON with timestamps and values), but the absent output schema does not severely hinder selection or invocation.

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 parameters are already documented. The tool description adds value by explaining parameter codes (00060, 00065, 00010) and mentioning query methods that map to schema properties. However, it does not elaborate on the period vs. start_dt/end_dt semantics, which the schema already covers.

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 it fetches real-time water data (streamflow, gage height, temperature) from USGS sites. It specifies the resource (USGS monitoring sites) and the verb (Get). However, it does not explicitly distinguish from the sibling tool 'usgs_daily_water_data', which likely provides historical daily averages versus real-time snapshots.

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 by listing query methods (site ID, state, county, HUC) and parameter code meanings. It does not provide explicit guidance on when to use this tool versus alternatives like 'usgs_daily_water_data' or 'usgs_water_sites', nor does it state when not to use it.

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