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

Annotations already declare readOnlyHint, destructiveHint, idempotentHint, and openWorldHint, indicating safe read-only behavior. The description adds value by listing the specific return fields (system name, PWSID, etc.) and the data source (EPA Safe Drinking Water Act data), which enriches agent understanding beyond annotations.

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 extremely concise: two sentences that cover purpose, scope, returned fields, and data source. No extraneous information. It is front-loaded with the main action.

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 tool's low complexity (simple search with two parameters), the description is complete. It explains what the tool does, what it returns, and the data source. The annotations cover behavioral aspects. The existence of an output schema (as per context signals) further reduces the need for more detail.

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 both parameters ('state' and 'limit'). The description does not add any extra detail about parameters (e.g., default limit of 10 is not mentioned). Since schema already covers them, a baseline score of 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 clearly states the verb 'Search' and the resource 'public water systems' with a specific scope 'by US state'. It lists the output fields, making the tool's purpose unambiguous. Sibling tools like 'epa.environment.toxic_releases' are different, so no confusion.

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 does not explicitly state when to use this tool versus alternatives, but the context of searching water systems by state is clear. No exclusions or alternative tool names are provided, which is acceptable for a straightforward search tool.

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