MCP and external tools
Symptoms
- the agent cannot get data from a knowledge base or another service;
- an MCP server does not connect;
- the server's tools do not appear in Tools;
- the agent sees the server but cannot perform the action you need;
- web search or a browser scenario does not work.
What to check
- Whether the server is added in the Explyt settings and is in the
Connectedstate. - Whether the address, the start command, and the server parameters are correct.
- Whether the required environment variables and credentials are passed.
- Whether the tool you need is allowed in the Tools menu.
- Whether the account has permission for the requested action.
Connection errors
Explyt shows the main message, the reason, the possible actions, and the technical details. The exact text from the server may differ, so rely on both the error title and its fields.
| Symptom or error | Where to look for the cause | What usually happened | What to do |
|---|---|---|---|
| Executable not found | The start command, executable, or the technical details | The path to the STDIO server is wrong, or the program is not available in the IDE environment | Specify an absolute path or add the program to the environment, then reconnect the server |
| The process exited on startup | The startup reason and the exit code | The command, arguments, or environment variables do not suit the server | Run the same command separately with safe test data, fix the parameters, and reconnect |
Connection Timeout | The connection stage and the timeout | The server did not start, respond to initialization, or return tools in time | Check the network and the server process, then run Reconnect; do not launch many retries in parallel |
Authentication Failed, HTTP 401 | The server response and the authorization headers | Credentials are missing, expired, or rejected | Authorize again or update the token in a secure storage or an environment variable |
Access Denied, HTTP 403 | The server response | The account is recognized but lacks permissions | Request the role you need or narrow the action to what is allowed |
Rate Limit, HTTP 429 | The server response, and Retry-After if present | The request rate or quota was exceeded | Wait for the stated period, reduce parallel calls, and retry once |
Handshake Incomplete | The initialize stage | The client and the server did not finish the MCP negotiation | Check the URL or transport, the server version compatibility, and the server log |
Tools Endpoint Failed | The list tools stage | The connection was established, but the server did not return the tool list | Check the permissions and the tools endpoint implementation, then run Reconnect |
| Protocol error or malformed response | The technical details and the server response | The server returned a message that does not conform to MCP | Update the server or fix its configuration; attach a sanitized fragment of the response to your support request |
The connection includes initialization and fetching the tool list. On Reconnect, Explyt requests the list again. A separate button that refreshes only the tool list is not confirmed by the current implementation.
After connecting
Start with a safe read-only request. If the server is connected but a tool is not visible, check that it exists on the server side, run Reconnect, and then open the Tools menu.
Do not store tokens in Markdown, in AGENTS.md, or in chat messages. For tools that change external data, keep the confirmation prompt on.
For frontend work you can connect Chrome MCP or Playwright MCP so the agent can see the result in the browser. For ordinary search and page reading, use Web Search.