search_companies
Search ARES by company name, city, street, PSČ, or NACE code. Combines all filters with AND. Useful when user knows name but not IČO, looking for companies in a building, or all businesses in a sector.
This record as markdown: /tools/dev-cz-agents-ares/search-companies.md
What search_companies does on Ares
AI agents call search_companies to retrieve information from Ares without modifying anything. It is typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
| Parameter | Type | Required | Description |
|---|---|---|---|
psc | integer | — | Filter by postal code (PSČ), 5-digit number. |
city | string | — | Filter by city (nazev obce), e.g. "Praha". |
nace | array | — | Filter by CZ-NACE activity codes, 2-6 digits. E.g., ["62"] for IT. |
pocet | integer | — | Max results (1-100, default 10). |
query | string | — | Partial or full company name (obchodní jméno). |
start | integer | — | Pagination offset (default 0). |
street | string | — | Filter by street name (nazev ulice), e.g. "Radlická". |
Parameters from the server's own tool schema.
Why search_companies is rated Low
The search_companies tool retrieves and queries publicly available company information from the Czech Business Register without modifying, deleting, or executing any operations. It is a passive read operation with no side effects. The combination of filters with AND logic is a standard query feature. Low severity reflects that misuse would only expose already-public business registry data.
From the tool's definition Tool performs 'search' operation on company registry using filter criteria (name, city, street, postal code, NACE code). The description explicitly states it 'searches' and 'looks for' companies, indicating query-only functionality.
Attacks that exploit this kind of access
The rule that runs search_companies safely
PolicyLayer is an MCP gateway: it sits between your AI agents and Ares, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For search_companies, this is the rule to start with:
search_companies is read-only, so it stays allowed. Everything else on the server is denied unless you say otherwise.
The button opens the PolicyLayer dashboard: create your workspace, connect Ares, apply this rule, and every search_companies call is checked against it from then on.
Questions about search_companies
Search ARES by company name, city, street, PSČ, or NACE code. Combines all filters with AND. Useful when user knows name but not IČO, looking for companies in a building, or all businesses in a sector. It is categorised as a Read tool in the Ares MCP Server, which means it retrieves data without modifying state.
search_companies accepts 7 parameters: psc, city, nace, pocet, query, start, street. The full parameter table on this page comes from the server's own tool schema.
Register the Ares MCP server in PolicyLayer and add a rule for search_companies: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches Ares. Nothing to install.
search_companies is a Read tool with low risk. Read-only tools are generally safe to allow by default.
Yes. Add a rate_limit block to the search_companies rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.
Set action: deny in the PolicyLayer policy for search_companies. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.
search_companies is provided by the Ares MCP server (https://ares.cz-agents.dev/mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
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