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

Annotations only declare readOnlyHint=true; the description adds real value beyond that by disclosing the breadth of the return payload (basic info, addresses, taxonomies/specialties, identifiers, other names) and pinning the backing API (NPPES Read API v2.1). It does not mention rate limits or error behavior for an unknown NPI, which keeps it short of a 5.

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?

Two sentences plus a provenance tag, all front-loaded: the lookup action and its constraining qualifier come first, the return contents second. Nothing is redundant with the title, and no sentence fails to earn its place.

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 one-parameter, read-only lookup with no output schema, the description supplies the input constraint, the identity of the operation, and a summary of what comes back. An agent has everything needed to call it correctly and interpret the result.

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 description coverage is 100% and the single 'number' parameter is already documented with the same pattern (^\d{10}$) and an example. The description reinforces the 10-digit/exact constraint but adds no syntax, format, or sourcing detail beyond the schema, so baseline 3 applies.

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 precise verb+resource+scope: look up a *single* provider by *exact* 10-digit NPI, then enumerates what the record contains (addresses, taxonomies, identifiers, other names). The words 'single' and 'exact' cleanly distinguish it from the sibling search tools without needing to name them.

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 phrasing 'single ... exact 10-digit NPI' implies when this beats a search tool, but the description never names nppes_search/nppes_search_individuals/nppes_search_organizations or states the condition (e.g., 'use search when you only have a name or partial NPI'). Usage is inferable but not explicit.

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