NPILayer

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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), so the description focuses on domain behavior and adds real value: the data source (CMS NPPES) and, more importantly, a list of things the record does NOT establish (licensure, credentialing, network participation, practice status). It does not address not-found handling or record freshness, which keeps it from 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, front-loaded with the operation and data source, and the second sentence uses its space to prevent a concrete misuse of the data. There is no redundant restatement of the title or schema.

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?

This is a low-complexity single-parameter lookup with a full input schema and an output schema, so return-value detail is unnecessary. The only meaningful omission is behavior on an unknown or invalid NPI, which would round out an otherwise complete definition.

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 has a type, a strict 10-digit pattern, and a concrete example. The description only restates that the input is a 10-digit NPI, adding no format, normalization, or edge-case guidance beyond the schema, so the 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?

The description gives a specific verb and resource ("Look up a single U.S. healthcare provider or organization"), names the exact identifier type, and explicitly narrows scope to a single record retrieved by NPI. That single-record, identifier-based framing naturally separates it from the sibling tools search_providers and providers_near 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 description makes the usage context clear (you already have a 10-digit NPI and want one record), and the caveat sentence implicitly tells the agent not to treat the result as credentialing evidence. However, it never explicitly says when to prefer search_providers or providers_near instead, so the routing decision is left to inference.

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

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.

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

Annotations already declare readOnly, idempotent, non-destructive, closed-world, so the safety profile is covered. The description adds a genuinely non-obvious behavioral fact — an unfiltered call returns an arbitrary page rather than a meaningful result — which prevents a real failure mode. Remaining gaps (max result cap, paging semantics) are partly handled by the page/limit schema and the presence of an output schema.

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, front-loaded with purpose and followed immediately by the actionable constraint. Nothing is redundant and every clause carries information the agent needs.

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 12-parameter, all-optional search tool with sparse schema coverage, the description covers the core intent and the empty-search pitfall but leaves filter-combination logic, specialty vs. taxonomy selection, and sibling disambiguation unaddressed. The output schema reduces the need to describe return values, which keeps this at a minimum-viable level rather than inadequate.

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 only 33% across 12 parameters, so the description must compensate, and it does so partially by naming the three filter families (name, location, specialty) that map onto name/first_name/last_name/organization, city/state/zip, and specialty/taxonomy/entity_type. It never clarifies the distinction between 'specialty' and 'taxonomy', nor how multiple filters combine, leaving several undocumented parameters unexplained.

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 and resource ('Search U.S. healthcare providers and organizations') plus the filter axes (name, location, specialty) and the upstream data source (CMS NPPES). It does not distinguish this tool from siblings like lookup_npi or providers_near, so the agent must infer that this is the general/free-text search rather than an NPI-exact or proximity lookup.

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?

Gives a concrete usage constraint and its consequence: 'Provide at least one filter; an empty search returns an arbitrary page.' That is useful when-to-use guidance, but there is no explicit routing to lookup_npi (known NPI) or providers_near (distance-based) despite those siblings being the obvious alternatives.

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