run_phone_enrichment_us

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

No annotations are provided, so the description must carry the behavioral burden. It discloses the tool validates and enriches, but does not explicitly state whether it is read-only, what happens on invalid input, or if any rate limits or permissions apply. This is a moderate disclosure level for a likely read-only enrichment tool.

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 single sentence that is front-loaded with the verb 'Validates and enriches' and is entirely free of filler. Every word adds value, and it fits the tool's simple scope.

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 its simplicity (1 parameter, no output schema), the description is nearly complete. It covers what the tool does and the input requirement. It lacks guidance on when to use this vs. run_phone_enrichment for international numbers, and does not mention error handling, but for a basic enrichment tool this is satisfactory.

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% - the single parameter 'phone' has a clear description and example. The tool description adds only that it's a US phone number, which is already in the schema, so no extra meaning is provided beyond reinforcing the format.

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 validates and enriches a US phone number, listing specific outputs: carrier, line type, activity score, litigator risk, and owner details. It distinguishes from sibling tools like run_phone_enrichment (non-US) and other enrichment tools by focusing on US phone numbers and specific enrichments.

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 says 'US phone number', giving clear context that this tool is for US numbers. However, it does not explicitly state when NOT to use it or mention alternatives like run_phone_enrichment for non-US numbers. The clear context earns a 4, but absence of exclusions keeps it from a 5.

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