co_water_readings

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

The annotations declare readOnlyHint: true, which is consistent with the description's 'Get' verb. The description adds useful context about measurement types and units, but does not disclose additional behavioral traits such as pagination, time zone handling, or that the 'real-time' claim may be misleading when date ranges are used. With annotations already covering the read-only safety profile, a 3 is appropriate.

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 well-structured: a one-sentence purpose, a compact parameter list with units, and a short usage note. It is front-loaded with the main function and every element earns its place without redundancy.

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 telemetry tool with a sibling station-finder, the description provides essential workflow context (use co_water_stations first) and parameter semantics. It does not detail return format or pagination, but no output schema exists and the tool's behavior is relatively straightforward. It is sufficiently complete for an agent to select and invoke the tool correctly.

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 covers all 5 parameters with descriptions, so the baseline is 3. The description adds value by listing each measurement parameter with its units (e.g., DISCHRG in CFS, STORAGE in acre-feet) and by clarifying that 'abbrev' comes from co_water_stations. This goes beyond the schema's terse enumeration.

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 retrieves real-time Colorado streamflow, reservoir, and weather telemetry readings, using a specific verb and resource. It does not explicitly contrast with sibling tools like co_water_stations, but the name and usage note imply differentiation, making it clear enough.

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 explicit guidance to 'Use co_water_stations first to find station abbreviations,' which is a clear prerequisite and directs the agent to the correct companion tool. However, it does not explicitly state when not to use this tool or mention alternatives for other data types, so it misses the top score.

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