Most problems fall into three groups: the client never connects, the client connects but some calls fail, or a call succeeds and the answer is wrong. Work down the section that matches what you are seeing.

The client never connects

Problem	Most likely
No ezeep tools appear at all	The endpoint was not accepted, and the failure is usually silent. Check the URL character by character, since a missing slash or a stray character in the host produces nothing rather than an error. Confirm the address starts with https, and confirm your client supports remote HTTP servers rather than local ones only. Where a configuration file is involved, a syntax error anywhere in that file can leave you with no tools and no message. Restart the client after any change.
Sign-in opens but never finishes	The browser window returns you to the client and nothing happens, or the loop repeats. Close the window, allow pop-ups and third-party cookies for the sign-in page, then start the connection again from the client rather than retrying in the browser.
Call fails with an authorization error	The sign-in never completed, or stored credentials have expired. Disconnect the server in your client and reconnect it, which forces a fresh sign-in. Reusing the existing connection will not re-authorize it.
It worked an hour and now it does not	Access tokens are short-lived. Reconnecting the server in your client resolves this.

The client connects but some calls fail

Problem	Most likely
A management call gets refused	Ask the assistant which ezeep account you are connected as. The response includes that account's roles, which tells you whether you are signed in as the identity you expected. Reconnect with the right account if not.
A connector call returns a bare error	That connector identifier does not exist. Ask for the connector list and use an identifier from it.
Job status reports an invalid job identifier	Either the identifier was mistyped, or it came from something other than a print submission. Job identifiers are returned when a job is submitted, and they are the only thing that tool accepts.

A call succeeds but the answer looks wrong

Problem	Most likely
A printer has no properties	A printer identifier that does not exist returns an empty result rather than an error, so an assistant can report this as "no properties" when the truth is "no such printer." Ask for the ezeep printer list, confirm the printer is on it, then ask again using the name exactly as it appears.
A list is shorter than you know it should be	Groups and connectors paginate, and the assistant may have read only the first page. Ask for the total count and compare, or ask it to fetch the remaining pages.
You asked which file types are supported and got a wall of configuration.	The underlying call returns the whole platform configuration with the extensions buried inside it. Ask for the file extensions specifically.
A user says they never received their invitation	A successful invite call creates the invitation without guaranteeing delivery, and an invitation whose email failed still displays as open with a future expiry date. Check its delivery state in the admin portal before sending another.
A job was accepted but nothing printed	The job is queued against its connector. Ask which ezeep connectors are offline first, because a job sent to a printer behind an offline connector is accepted and then waits. Check the job status after that.

When the problem is not the MCP server

A healthy connection that lists printers correctly means the MCP server is doing its job, and a print problem at that point is an ordinary ezeep print problem. Check the connector, the printer and the job in the admin portal the way you would for any other job. Nothing about MCP changes how jobs are handled once they are submitted.

ezeep MCP server tools covers what each tool returns, which helps when an answer looks wrong rather than absent.