Get Real-Time Water Data

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

Annotations already indicate read-only, idempotent, open-world behavior. The description adds valuable context: update frequency (15 minutes) and coverage (rivers, streams, lakes, reservoirs across US), enhancing transparency beyond annotations.

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?

Three short sentences with no unnecessary words. Purpose, update frequency, coverage, and prerequisite are all front-loaded. 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?

For a simple data retrieval tool with output schema, the description covers main purpose, update frequency, geography, and prerequisite tool. It omits details about output format, but output schema exists so not required. Adequate context for an agent.

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 coverage is 100% with detailed descriptions for each parameter (site_no, parameter_cd with common codes, period with ISO 8601 format). The tool description provides a high-level overview but does not add significant meaning beyond the schema, so baseline 3 is appropriate.

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 what data is retrieved (streamflow, gage height, temperature, conductance), update frequency (15 minutes), geographic scope (US), and points to the companion tool water.sites for finding site numbers. This distinguishes it from siblings.

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 explicitly references water.sites as a prerequisite to find site numbers, providing clear usage guidance. It does not state when not to use, but the purpose is focused.

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