co_water_stations

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

The annotations already declare readOnlyHint: true, so the description's job is lighter. It adds useful context about the return payload: station abbreviations, location, parameter type, and metadata, which helps the agent understand what to expect without an output schema. It does not disclose details like pagination or default values, but those are partially covered by the schema.

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 two-sentence, front-loaded summary. The first sentence states the core purpose, and the second provides return value information. There is no filler or redundant repetition of schema details, making it 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?

The description covers the essential aspects: what the tool does, what it returns, and its relationship to co_water_readings. With no output schema, it provides enough context for a search tool. It could be slightly more complete by clarifying behavior when no filters are supplied, but overall it is sufficient for an agent to select and use it effectively.

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 has 100% coverage with descriptions for all four parameters, including the filter fields (county, division, water_district) and limit. The description restates these filters but does not add new details such as how multiple filters interact or the default limit behavior, so it adds only marginal value beyond the schema.

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 function: 'Search Colorado telemetry stations — find monitoring stations by county, water district, or division.' It uses a specific verb ('search'), a resource ('Colorado telemetry stations'), and the filtering scope, making it easy to distinguish from sibling tools like co_water_readings.

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 mentions that the tool 'Returns station abbreviations needed for co_water_readings,' which tells the agent when to use this tool (before querying readings). However, it does not explicitly state when not to use it or compare it to other alternatives like cdec_stations, though the Colorado focus provides some implicit differentiation.

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