MCP Servers for Agents
Summary
MCP servers connect external tools to an agent: CRM, knowledge base, API, or another service. An agent can use individually selected servers or a shared set whose contents change for every connected agent at once.
Connect MCP to an agent only when the tool is actually needed in answers or actions. The broader the toolset, the more important it is to clearly describe in the agent instruction when tools may be called and which data must not be sent outside.
Choose A Connection Mode
Open the MCP settings in the agent form and choose one of four modes:
- No MCP servers gives the agent no MCP tools;
- Directly through the AI provider lets the provider call selected servers itself. The server must be publicly reachable over HTTPS;
- Selected servers through Senler lets Senler call the specific servers selected for this agent;
- Server set through Senler connects a shared set. Use it when several agents need the same tool collection.
Not every AI model supports all four options. Modes through Senler require the selected model to call standard tools. Directly through the AI provider additionally requires the model and its active provider connection to support native MCP and tool catalog loading. No MCP servers is available with every model.
When you select another model, the cabinet compares its capabilities with the current MCP mode. If the mode is unsupported, a Change the MCP mode? dialog shows the current and replacement options. Change model and mode applies both changes, while Cancel model change keeps the previous settings.
If the model cannot connect directly through the AI provider but can use tools through Senler, the cabinet offers Selected servers through Senler. If the model does not support that option either, the replacement is No MCP servers. You also cannot save an incompatible combination after changing the settings manually.
Select Servers Or A Set
In either individual-server mode, select Add server, use search, choose the required servers, and select Apply. You can remove a selected server from the agent.
You can also find an MCP server through the @ button in the instructions. If the current mode already allows it, the cabinet inserts its tag immediately. Otherwise, MCP settings open: select a compatible mode and server and save them, after which the tag is added to the instructions. The tag does not replace a rule; state next to it when and for which task the server tools should be called.
In server set mode, choose an existing set. Next to the field, you can create a set or edit the selected set. Sets are also available in MCP server settings.
Confirm with Save, save the agent draft, test the tool, and publish a new version. Changes to the mode, selected servers, or selected set reach live dialogs after the agent is published.
Editing the contents of a connected set updates every agent that uses that set. Those agents do not need to be published again.
If servers or sets do not load
If the cabinet cannot retrieve the data required by the selected mode, the MCP dialog shows a message with Retry. In server set mode it reloads the sets; in an individual-server mode it reloads the server list.
Save remains unavailable until the required data loads. After a successful retry, review the selection again before saving the settings.
If the tool is not used
- check whether the MCP server is selected in the agent settings;
- for provider-direct mode, check that the server address is publicly reachable over HTTPS;
- if a set is connected, check its current contents;
- check whether the selected model supports the current MCP mode; otherwise confirm the proposed mode change or choose another model;
- check if a new version of the agent has been published;
- check if the agent is active;
- check the authorization of the MCP server;
- check “History” for tool start, completion, and error events.
Related Elements
- agent settings form
- agent list
- Agents item in the side menu