Skip to main content
Glama

UK Due Diligence

by io.github.paulieb89

Get Persons with Significant Control

company_psc
Read-onlyIdempotent

Fetch Persons with Significant Control (beneficial ownership) for a company.

Returns PSC entries with natures of control, nationality, and country of residence. Flags overseas corporate PSC entries as a beneficial ownership risk signal. Returns an explanatory note for widely-held PLCs with no registrable PSC.

Input Schema

TableJSON Schema
NameRequiredDescriptionDefault
company_numberYesCompanies House company number (8 digits, e.g. '03782379'). Returned by company_search.

Output Schema

TableJSON Schema
NameRequiredDescriptionDefault
pscNoPersons with Significant Control records.
noteNoExplanatory note when total=0. Typical for widely-held listed PLCs where no single person or entity holds 25%+ of shares or voting rights.
totalYesTotal PSC entries returned for this company.
company_numberYesCompanies House company number.
overseas_corporate_psc_flagNoNumber of corporate PSCs registered outside the UK. Non-zero values indicate an offshore beneficial ownership chain.

Schema Changelog

Changes observed during successful MCP inspections. Dates show when Glama detected each change.

  1. Changed1 schema field changed
    • addedOutput schema / properties / psc / items / properties / date_of_birth
      Added value: +{
+  "additionalProperties": true,
+  "description": "Partial date of birth (month/year) for individual PSCs as returned by CH.",
+  "type": "object"
+}
  2. Added
  3. Removed
  4. Changed1 schema field changed
    • changedOutput schema / properties / psc / items / properties / natures_of_control / description
      Previous value: -"List of 'nature of control' descriptors (e.g. 'ownership-of-shares-75-to-100-percent'). Individual entries may be truncated per the `max_nature_chars` input."New value: +"List of 'nature of control' descriptors (e.g. 'ownership-of-shares-75-to-100-percent'). Individual entries may be truncated to 300 characters each."
  5. Added
  6. Removed
  7. Changed10 schema fields changed
    • addedInput schema / properties / max_nature_chars
      Added value: +{
+  "default": 300,
+  "description": "Per-entry cap on each 'nature of control' descriptor. Upstream entries are sometimes long legal text. Default 300.",
+  "maximum": 5000,
+  "minimum": 50,
+  "type": "integer"
+}
    • removedInput schema / properties / response_format
      Removed value: -{
-  "default": "markdown",
-  "description": "Output format: 'markdown' or 'json'",
-  "type": "string"
-}
    • changedOutput schema / description
      Previous value: -"Generic wrapper for non-object return types."New value: +"List of Persons with Significant Control for a company."
    • addedOutput schema / properties / company_number
      Added value: +{
+  "description": "Companies House company number.",
+  "type": "string"
+}
    • addedOutput schema / properties / overseas_corporate_psc_flag
      Added value: +{
+  "default": 0,
+  "description": "Number of corporate PSCs registered outside the UK. Non-zero values indicate an offshore beneficial ownership chain.",
+  "type": "integer"
+}
    • addedOutput schema / properties / psc
      Added value: +{
+  "description": "Persons with Significant Control records.",
+  "items": {
+    "description": "A single Person with Significant Control record.",
+    "properties": {
+      "address": {
+        "additionalProperties": true,
+        "description": "PSC correspondence address.",
+        "type": "object"
+      },
+      "ceased_on": {
+        "anyOf": [
+          {
+            "type": "string"
+          },
+          {
+            "type": "null"
+          }
+        ],
+        "default": null,
+        "description": "Date PSC status ceased, if applicable."
+      },
+      "country_of_residence": {
+        "anyOf": [
+          {
+            "type": "string"
+          },
+          {
+            "type": "null"
+          }
+        ],
+        "default": null,
+        "description": "Declared country of residence for individual PSCs."
+      },
+      "identification": {
+        "additionalProperties": true,
+        "description": "Identification block for corporate PSCs: place_registered, registration_number, country_registered, legal_authority, etc.",
+        "type": "object"
+      },
+      "kind": {
+        "anyOf": [
+          {
+            "type": "string"
+          },
+          {
+            "type": "null"
+          }
+        ],
+        "default": null,
+        "description": "Upstream 'kind' (e.g. 'individual-person-with-significant-control', 'corporate-entity-person-with-significant-control')."
+      },
+      "name": {
+        "anyOf": [
+          {
+            "type": "string"
+          },
+          {
+            "type": "null"
+          }
+        ],
+        "default": null,
+        "description": "PSC name (individual or entity)."
+      },
+      "nationality": {
+        "anyOf": [
+          {
+            "type": "string"
+          },
+          {
+            "type": "null"
+          }
+        ],
+        "default": null,
+        "description": "Declared nationality for individual PSCs."
+      },
+      "natures_of_control": {
+        "description": "List of 'nature of control' descriptors (e.g. 'ownership-of-shares-75-to-100-percent'). Individual entries may be truncated per the `max_nature_chars` input.",
+        "items": {
+          "type": "string"
+        },
+        "type": "array"
+      },
+      "notified_on": {
+        "anyOf": [
+          {
+            "type": "string"
+          },
+          {
+            "type": "null"
+          }
+        ],
+        "default": null,
+        "description": "Date notified as a PSC (ISO YYYY-MM-DD)."
+      }
+    },
+    "type": "object"
+  },
+  "type": "array"
+}
    • removedOutput schema / properties / result
      Removed value: -{
-  "type": "string"
-}
    • addedOutput schema / properties / total
      Added value: +{
+  "description": "Total PSC entries returned for this company.",
+  "type": "integer"
+}
    • changedOutput schema / required
      Previous value: -[
-  "result"
-]New value: +[
+  "company_number",
+  "total"
+]
    • removedOutput schema / x-fastmcp-wrap-result
      Removed value: -true
  8. First observed

TDQS

A4.3/5.0
Behavior4/5

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

Annotations already cover read-only, idempotent, and non-destructive behavior. The description adds meaningful behavioral detail beyond that: it returns natures of control, nationality, and country of residence; flags overseas corporate PSC entries as a beneficial ownership risk signal; and returns an explanatory note for PLCs with no registrable PSC. This gives an agent useful expectations about non-obvious outputs.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is three concise sentences with no fluff. The first sentence states the core action clearly, and the following sentences list return contents and edge-case behavior. Every sentence adds value, and the structure supports fast agent scanning.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness5/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a single-parameter, read-only tool with a full input schema and an output schema, the description is complete. It explains the primary output, the risk flag, and the no-PSC edge case. Nothing essential is missing for correct selection and invocation.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so the schema already documents company_number, including format, length, and that it is returned by company_search. The tool description itself adds no additional parameter-level semantics; the baseline of 3 is appropriate because the schema carries the burden.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description opens with a specific verb and resource: 'Fetch Persons with Significant Control (beneficial ownership) for a company.' This precisely names both the action and the entity type, and distinguishes the tool from siblings like company_officers or company_profile by focusing on PSC/beneficial ownership.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines4/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description states the intended context by explaining what kind of data is returned and when a special note is provided for widely-held PLCs. It does not explicitly name alternative tools for comparison, but the PSC/beneficial ownership framing makes the appropriate use case clear enough for an agent to choose this tool over sibling company_* tools.

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

All UK Due Diligence toolsInspect
Try in Browser
RayrunBuild, deploy, and operate MCP servers without becoming an infrastructure team.ray.runAd

Glama MCP Gateway

Add one secure layer between your agents and this server.

TDQS

A4.2/5.0
Disambiguation4/5

The domain-specific tools are clearly distinct (search vs profile for each register), and the generic search/fetch tools are designed to route across them. Potential overlap between company_officers and company_psc is resolved by clear descriptions of officers vs beneficial ownership. Slight ambiguity exists between generic fetch/search and the domain-specific counterparts, but the routing logic is well-documented.

Naming Consistency4/5

Most tools follow a consistent resource_action pattern with clear prefixes (charity_, company_, disqualified_, gazette_). Exceptions like company_officers, company_psc, sanctions_screen, and vat_validate deviate from the verb-first convention, and generic tools (fetch, search, get_prompt, list_prompts) do not follow the pattern. Overall, the naming is readable and predictable despite a few outliers.

Tool Count4/5

With 17 tools, the server sits slightly above the typical 3-15 well-scoped range, but the breadth of the domain (Companies House, Charity Commission, disqualifications, Gazette insolvency, sanctions, land registry, VAT) justifies the count. Each tool serves a distinct data source or action, and the two prompt-management tools are standard MCP utilities. The count feels appropriate rather than excessive.

Completeness4/5

The server covers the core due diligence workflow: searching and retrieving profiles for companies, charities, and disqualified directors, plus insolvency notices, sanctions screening, land transactions, and VAT validation. Minor gaps exist, such as no direct tool for company accounts or court judgments, but these are not core to the apparent purpose and can be worked around.

Resources