When the assistant can't connect or a tool fails
Connection errors, tool errors, and the limits for results and runtime.
- For
- Anyone whose assistant can't reach Szenera or reports an error from a tool
- Prerequisite
- none
On this page
Connection errors show up before a conversation starts, tool errors in the middle of one. This page lists both by what you see, and the limits the server sets for results and runtime.
The connection fails
The server checks your credential against the platform at the start of a session and on every later request. The session identifier alone opens nothing.
| What you see | Meaning | Solution |
|---|---|---|
401 with error="invalid_request" |
The request carries no credential. | Sign in through OAuth, or send Authorization: Bearer ak_…. |
401 with error="invalid_token" |
The platform rejected the credential: expired, revoked, or mistyped. | Sign in again, or use a valid key. An access token oat_… is valid for one hour. |
404 with {"error": "no_session"} |
The session has expired. It lives for 24 hours and every call extends it. | Nothing to do: the client starts a new session by itself. Reconnect if it doesn't. |
400 with {"error": "no_session_id"} |
The header Mcp-Session-Id is missing or malformed. |
Use a client that follows the MCP specification. |
| The sign-in fails right away | The client didn't pass on the permissions (scope) the server names, and the authorization server rejects a request without them. |
Update the client. The permissions are in the resource metadata and in the 401 answer. |
A 401 always carries the header WWW-Authenticate with the address of the resource metadata, so a client that supports OAuth knows where to sign in.
A tool fails
A failed tool answers with three fields: error, hint (one sentence in English), and correlationId, with which the operations team finds the call again.
error |
Meaning | Solution |
|---|---|---|
unauthenticated |
The platform rejected the credential (401). |
Sign in again. |
permission_denied |
The credential lacks the permission (403). The hint names the area. |
Allow the area again, or use a key with the permission, see Permissions and consent. |
not_found |
There is nothing with this identifier in your organization (404). |
Take the identifier from a list fetched with the same credential. |
conflict |
The object changed since it was read (409). |
Read it again and decide again. |
invalid_input |
The platform rejected the values (422). |
Check the values. Field paths from the platform's answer are kept. |
no_seat_available |
All booked seats of your organization are taken (402). |
Book another seat in the portal, or delete a display you no longer need. |
rate_limited |
The rate limit is used up (429). |
Wait and try again, see Throttling and rate-limit headers. |
platform_unreachable |
The API doesn't answer. | Try again later. The server can do nothing without it. |
timeout |
The time for the call has run out. | Ask a narrower question, for example with a filter or a smaller list. |
canceled |
The call was canceled, for example because the connection dropped. | Call it again. |
unexpected |
The platform answered in a way the server can't classify. | Try again later, and give the correlationId to support. |
A writing tool does nothing
That is the preview. Without confirm: true, a writing tool reads the current state and answers with "status": "preview" and "executed": false. The assistant shows you the effect and calls the tool again with the same values and confirm: true. Only then does it answer "status": "executed".
Limits
| Limit | Default |
|---|---|
| Runtime of a tool call | 30 seconds |
| Runtime of a single call to the API | 15 seconds |
| Length of a result | 20,000 characters, anything beyond that is visibly cut off |
| Entries in a list | 50 per answer, which also caps the requested page size |
| Idle session | 24 hours, every call extends it |
The operator of your environment can set these values differently.
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