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

Annotations already cover read-only, open-world, idempotent, and non-destructive hints. The description adds useful behavioral context beyond annotations by stating the dataset coverage ('150,000+ US public water systems') and data source provenance ('EPA SDWIS Federal Reporting Services, US Gov public domain'). It does not contradict annotations and provides extra context.

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 four sentences, each adding substantial value: the search action, return fields, dataset scale and provenance, and a pointer to a sibling tool. It is front-loaded with the primary purpose and has no filler or 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?

Given the fully described schema (100% coverage), explicit annotations, and presence of an output schema, the description provides all necessary contextual information: what data is covered, where it comes from, what can be filtered, and what to use for violations. Nothing essential appears missing.

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 descriptions for every parameter. The description repeats some parameter semantics (e.g., type enumeration, activity status) but introduces no new meaning beyond the schema, such as the limit parameter behavior or defaults. The description's mention of filters is redundant with the schema's descriptions, 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 states a specific verb-resource-filters combination: 'Search EPA Safe Drinking Water Information System (SDWIS) for public water systems by state, system type..., and activity status.' It lists returned fields (PWSID, system name, population, etc.) and clearly differentiates the tool's scope from sibling sdwis.water.violations by stating the latter is for health violations.

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 directs users to sdwis.water.violations for checking health violations, which provides clear routing for a primary alternative. It does not mention when not to use this tool for other sibling concerns (e.g., service areas, enforcement), but the given guidance is specific and actionable.

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