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 only lists output categories and does not state whether the operation is read-only, how recent the latest reading is, what happens for an invalid slug, or any data-freshness details. This is thin for a tool with zero annotation coverage.

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 a single compact fragment with no filler. The core idea of 'one reservoir' is front-loaded, and the examples earn their place by clarifying the slug parameter.

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 one-parameter lookup, the high-level output description is passable, but the absence of an output schema and annotations leaves gaps around units, series date range, and error behavior. An agent could invoke it correctly but would still have limited understanding of the full response.

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 schema only provides a 'Slug' title with 0% description coverage. The description compensates by giving concrete example slugs (lake-mead, elephant-butte) and indicating that the slug selects one reservoir. It does not enumerate all valid slugs or specify formatting rules, but it adds meaningful value for the only required parameter.

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 identifies the resource as a single reservoir and lists what is returned: capacity basis, latest reading, and series. The singular 'One reservoir' distinguishes it from the sibling 'reservoirs' tool, though it lacks an explicit verb like 'get' or 'retrieve'.

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 phrasing 'One reservoir' implies this tool is for a specific reservoir rather than a list, and the examples hint at valid slugs. However, it does not explicitly name alternatives or state when not to use it, leaving usage guidance mostly implicit.

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