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

Annotations already establish read-only, idempotent, non-destructive, closed-world behavior, so the bar is lower. The description still adds a genuinely important accuracy caveat: distance is measured from each provider's primary practice location to the ZIP centroid, not a street address, which materially affects how results should be interpreted.

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?

Three sentences, no filler. The purpose comes first, the required-input rule second, and the geographic caveat last, which is exactly the order an agent needs them.

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 zero required parameters across nine properties, the description correctly supplies the selection rule for the location inputs, and an output schema exists so return values need not be explained. The remaining gap is that taxonomy, specialty, and entity_type filtering are left entirely to the schema, and no note hints at how those filters combine.

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 78%, above the high-coverage threshold, so the schema does most of the work and a baseline of 3 applies. The description adds one real constraint not encoded in the schema (the zip vs lat+lng either/or rule); it says nothing about radius defaults, taxonomy vs specialty interplay, or limit/page behavior beyond what the properties already state.

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?

States a specific verb ('Find'), resource ('U.S. healthcare providers'), spatial scope ('within a radius of a ZIP code or coordinate') and data source ('CMS NPPES'). It does not, however, distinguish itself from the sibling search_providers, so an agent cannot tell from the description alone which one to reach for.

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?

It gives concrete input guidance ('Provide either "zip", or both "lat" and "lng"'), which is the main usage decision for this tool. But it offers no when-to-use vs search_providers or lookup_npi comparison, and no stated limits on when a radius search is inappropriate.

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