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

Annotations already declare readOnlyHint=true, openWorldHint=true and destructiveHint=false, so the safety profile is covered. The description adds genuine value with the 'NPI-2 only' scope and the 'HIPAA safe harbor' compliance note, but says nothing about rate limits, pagination behavior past the limit param, or what an empty/unconstrained query returns.

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?

A single front-loaded sentence with a verb, resource, scope and compliance note; every clause earns its place and nothing is padded.

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 six all-optional parameters and no output schema, the definition should say what an unconstrained call returns and roughly what fields come back (name, address, taxonomy, NPI). The compliance and scope notes help, but response behavior remains unexplained.

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 six self-documented parameters, so the schema carries the load. The 'NPI-2 only' constraint does add meaning to the 'number' parameter (individual NPIs will not match), but the description does not explain how the optional filters combine or what happens when none are supplied.

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+resource (NPI Registry lookup) and scopes it to healthcare organizations and facilities, which no sibling tool covers. The 'NPI-2 only' qualifier sharpens the target, though the description never names the API's operator beyond 'CMS NPPES'.

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 'NPI-2 only' clause implicitly excludes individual-provider (NPI-1) lookups, which is a useful boundary. However there is no explicit when-to-use guidance, no suggestion of which parameter combinations to prefer (number vs name+state+city), and no mention of alternatives for individual providers.

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