Certified IRS ITIN acceptance agents directory by state — fees, languages, services.
Scored across 6 tools
Each tool has a clearly distinct purpose: get_listing fetches one record by slug, get_stats returns aggregate counts, and list_categories/list_places/list_sources each enumerate a different facet. search_listings is the only query tool and does not overlap confusingly with the list tools, since it searches listings rather than metadata facets.
All names follow a consistent verb_noun pattern (get_*, list_*, search_*), with no mixed casing or verb styles. Singular/plural nouns are used semantically (get_listing vs. list_categories) but the pattern itself is predictable.
Six tools is well-scoped for a read-only directory API: one detail fetch, one aggregate stats call, three facet lists, and one search. No tool feels redundant or out of place.
The surface covers the core read-only directory workflow: search, detail lookup, facet browsing, and data provenance. Minor gaps exist, such as no explicit list-all-listings endpoint or pagination controls, but agents can work around these using search_listings.
Get one published ITIN acceptance agent by its slug.
| Name | Required | Description | Default |
|---|---|---|---|
| slug | Yes | The listing slug. |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnly, idempotent, non-destructive, and closed-world behavior, so the safety profile is covered. The description adds one useful behavioral detail — only 'published' listings are returned, implying non-published slugs fail — but says nothing about error/not-found behavior.
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 tight sentence with zero filler, and the resource identity is front-loaded after the verb. Nothing could be removed without losing meaning.
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 lookup with annotations covering safety, the definition is mostly adequate, but with no output schema it never indicates what a successful response contains or what happens on a missing/unpublished slug. That leaves a modest gap for an agent.
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 slug parameter is fully documented in the schema (type, pattern, length bounds). The description only restates 'by its slug' without adding format or resolution semantics, 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 specific verb ('Get') and resource ('one published ITIN acceptance agent'), clarified by the singular lookup semantics that distinguish it from the sibling search_listings/list_* tools. It does not explicitly name those alternatives, so it falls short of a 5.
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 phrase 'by its slug' implies you must already hold a known slug, which quietly separates it from search_listings, but there is no explicit when-to-use, when-not, or prerequisite statement. Usage is only inferable.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Get the number of published ITIN acceptance agents, places and categories, and when the data last changed.
| Name | Required | Description | Default |
|---|---|---|---|
No parameters | |||
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the safety profile is covered. The description adds value beyond them by disclosing the returned content — counts per entity type plus a last-changed timestamp — which matters because there is no output schema to convey this.
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 stating scope and return content with no filler. Every clause earns 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 parameterless, annotation-covered tool with no output schema, the description supplies the essential missing piece: what the response contains and that it includes a freshness indicator. It does not clarify whether counts are global or filtered, but for this tool shape that is a minor gap.
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?
The tool takes zero parameters, so per the baseline this dimension scores 4. The description adds nothing parameter-related, but there is nothing to document.
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 ('Get the number of') plus an explicit enumeration of the resources counted (ITIN acceptance agents, places, categories) and the freshness field. This clearly separates it from listing siblings like get_listing, list_places, and list_categories, which return records rather than aggregates.
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?
Usage is only implied: the aggregate nature of the tool suggests it is for counts/overview rather than data retrieval, but the description never states when to prefer it over get_listing or the list_* siblings, nor any prerequisites. No exclusions or alternatives are named, so the agent must infer the routing.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
List categories with their ITIN acceptance agent counts.
| Name | Required | Description | Default |
|---|---|---|---|
No parameters | |||
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and openWorldHint=false, covering the full safety profile. The description adds that results are paired with agent counts, which is useful return-shape context, but says nothing about ordering, completeness, or pagination. With annotations doing the heavy lifting, this sits at an adequate 3.
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 sentence with no filler, and the key content (category listing plus counts) is front-loaded immediately.
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 zero-parameter, read-only tool with no output schema, the description supplies the essential return shape (categories plus ITIN acceptance agent counts) and the annotations cover safety. Ordering, completeness, and how counts are scoped remain unspecified, which is a minor gap given the tool's simplicity.
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?
The tool takes zero parameters, so the baseline is 4 and there is no parameter behavior for the description to explain or omit.
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 states a specific verb and resource ('List categories') plus the payload it carries ('ITIN acceptance agent counts'), so an agent knows exactly what the tool returns. It does not, however, contrast itself with the sibling list tools (list_places, list_sources, get_listing), so differentiation is left to inference.
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?
There is no statement of when to use this tool versus the alternatives (get_stats, list_places, list_sources) or any precondition. The purpose is implied by the name alone, which is the minimum, not guidance.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
List countries, regions and cities that have ITIN acceptance agents.
| Name | Required | Description | Default |
|---|---|---|---|
No parameters | |||
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare this a safe, idempotent read (readOnlyHint, idempotentHint, destructiveHint false), so the safety burden is lifted. The description adds the useful scoping fact that only places with acceptance agents are returned, but says nothing about result size, ordering, or the country/region/city hierarchy structure.
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 no filler; the filtering condition (ITIN acceptance agents) is stated right in the scope clause. Nothing could be trimmed without losing meaning.
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 zero-parameter enumeration tool with no output schema, the description conveys the entity set and the filtering condition adequately, and annotations cover safety. It stops short of describing the nesting or ordering of countries/regions/cities, which would help an agent use 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?
The tool takes zero parameters, so the baseline for this dimension is 4 and the schema has nothing to document. There are no parameter semantics the description could or should add.
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 ("List") and a precisely scoped resource (countries, regions and cities that have ITIN acceptance agents). The resource is clearly distinct from the sibling list tools (list_categories, list_sources), so an agent can route without opening a schema.
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 stated scope implies when an agent would call it (enumerating geographic coverage of ITIN acceptance agents), but it never states when to use it versus a sibling or any prerequisites. Usage is inferable rather than explicit.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
List where the ITIN acceptance agent data comes from, with the license and refresh of each source.
| Name | Required | Description | Default |
|---|---|---|---|
No parameters | |||
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint, idempotentHint, non-destructive, and closed-world, so the safety profile is fully covered. The description adds that each source entry carries license and refresh information, a modest return-content detail. No mention of pagination, auth, or rate limits.
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?
One sentence, front-loaded with the verb and resource, and every clause earns its place by naming the domain and the per-source attributes returned.
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 zero-parameter listing tool with no output schema, the description is close to complete: it says what is listed and what each entry contains (license, refresh). Only the absence of any usage framing keeps it from full marks.
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?
The tool takes zero parameters, so the schema bears no semantic burden and the 4 baseline applies. The description adds nothing parameter-related, which is correct here.
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 (List) and resource (sources of ITIN acceptance agent data), and clarifies the domain of 'sources' beyond the tool name alone. It does not explicitly contrast with siblings like list_categories or search_listings, but the resource is distinct enough that an agent won't confuse 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?
Usage is only implied: 'List where ... comes from' suggests consulting provenance information, but there is no statement of when to call this versus get_stats or list_categories, nor any prerequisites. Adequate but with a clear guidance gap.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Search published ITIN acceptance agents by text, place and category.
| Name | Required | Description | Default |
|---|---|---|---|
| q | No | Search text, with at least one letter or digit. Matches name, categories, attributes, description and place. Typos fall back to close matches. | |
| city | No | City slug, from /places. | |
| sort | No | `relevance` needs `q` and is the default with it. `name` is the default without `q`. `recent` is newest first. | |
| limit | No | Items per page. | |
| cursor | No | `page.nextCursor` from the previous response. Opaque. Send the same filters and `limit`. | |
| region | No | Region slug, from /places. | |
| country | No | ISO 3166-1 alpha-2 country code, any case. A country the directory does not cover, as listed in /places, gives 400. | |
| category | No | Category slug, from /categories. A parent slug also matches its children. |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint, idempotentHint, non-destructive, and a closed world, so the safety profile is covered. The description adds one genuine behavioral constraint not in the annotations: results are limited to *published* agents, implying unpublished/removed entries are excluded. It says nothing about pagination cost or result ordering behavior.
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 no filler. Every word earns its place: verb, resource, and the three search dimensions.
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 no output schema, the description does not describe the return shape (that it returns a paged result set with page.nextCursor), which the cursor parameter only implies. Annotations and 100% parameter coverage make the definition usable, but the result contract is left entirely to inference.
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%, with per-parameter detail on matching scope, sort defaults, cursor opacity, and place/category slug sources. The description adds nothing beyond that baseline, so a 3 is correct when the schema carries the parameter burden.
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 uses a specific verb (Search) and a precise resource (published ITIN acceptance agents) and names the three filter axes (text, place, category). It is clearly distinguishable from get_listing (single-fetch) and list_places/list_categories (reference lists), though it never explicitly contrasts itself with 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?
There is no when-to-use or when-not-to-use guidance, and no sibling is named as an alternative. The schema hints that slugs come from /places and /categories, but the description itself offers no routing context for choosing search_listings over list_places or get_listing.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Recent tool additions, removals, and schema changes observed during successful MCP inspections.
get_listingget_statslist_categorieslist_placeslist_sourcessearch_listings
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