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

Annotations already cover read-only, idempotent, non-destructive behavior. The description adds provenance ('EPA SDWIS Federal Reporting Services'), public-domain status, returned fields, and example enforcement categories, going beyond the structured hints.

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?

Four sentences, front-loaded with the core lookup statement, filters, and return fields. The data-source sentence is useful provenance and no sentence is filler, though it is slightly longer than strictly necessary.

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 three-param tool with full schema coverage, safety annotations, and an output schema, the description is nearly sufficient. It clearly explains the filters, return fields, and companion tool; the only minor gap is behavior when no filters are supplied.

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%, so the schema already documents all three parameters and the baseline is 3. The description adds some context such as PWSID expansion and enforcement category examples, but largely restates the schema's pwsid and action_type meanings and omits limit.

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?

Opens with a specific verb+resource: 'Look up EPA enforcement actions taken against public water systems under the Safe Drinking Water Act.' It clearly frames itself as the enforcement-history counterpart to sdwis.water.violations and lists concrete return fields.

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?

Gives concrete selection criteria: filter by PWSID for a utility's full enforcement history or by action type code. It recommends pairing with sdwis.water.violations for the full compliance picture, though it does not explicitly state when not to use this tool.

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