epa_drinking_water

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

Annotations already declare readOnlyHint=true, and description adds meaningful detail: explains the system type codes (CWS, NTNCWS, TNCWS) with examples, and indicates the tool returns population served and source type. This is valuable context beyond the annotation, though it does not discuss response format or rate limits.

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?

Description is compact yet informative: a lead sentence stating the resource, three sentences listing return fields and system type definitions, and a final sentence suggesting cross-reference use. No wasted words; each sentence adds distinct value.

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?

With no output schema, the description adequately explains what data is returned (population, source type, system type) and defines enum-like values inline. It could mention pagination or the rows parameter default, but that is already in the schema. Overall sufficient for a moderately simple read-only tool.

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 both parameters (state and rows) with descriptions and defaults, achieving 100% coverage. The tool description reiterates the 'by state' nature but adds no extra parameter-level syntax or behavior beyond what the schema already provides. Per guidance, baseline 3 applies when schema coverage is high.

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?

Description uses specific verb 'Get' and resource 'Safe Drinking Water Information System (SDWIS) data by state', clearly distinguishing it from other EPA tools like epa_facilities or epa_toxic_releases. It also summarizes the returned data types (population served, source type, system type), leaving no ambiguity about scope.

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?

Provides clear context: use when needing SDWIS drinking water data by state, and suggests cross-referencing with CDC and Census for per-capita analysis. It does not explicitly name alternatives or when not to use, but the purpose is specific enough to infer appropriate usage.

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