Error reference

The tool-error messages Studio returns and what to do about each.

Failed tool calls come back as MCP tool errors (isError: true) whose text is a short, stable message. They are not exceptions — the call completes, and the message tells you what to do next.

Posts

Message	Meaning	Fix
not_found	No such post in this studio	Check the id; ids don’t cross studios
cannot_edit_scheduled_post	Retargeting a scheduled post	unschedule_post first
cannot_edit_posted_post	Editing something already live	Create a new draft
post_modified_concurrently	The row changed mid-update	Re-read with get_post and retry
dispatch_in_progress	Deleting a queued post	Wait for it to settle

Publishing and scheduling

Message	Meaning	Fix
only_draft_can_be_published	Post isn’t a draft	Check status first
specify_platform	Post targets several platforms	Pass platform
post_does_not_target_x	Requested platform isn’t a target	Update targetPlatforms or pick another
content exceeds 3000 characters for linkedin	Body over the platform limit	Shorten the content
not_connected	Platform isn’t linked to this studio	connect_platform
token_expired	Stored token can’t be refreshed	Reconnect the platform
scheduled_at_must_be_future	Timestamp is past or unparseable	Send ISO 8601 with an offset, in the future
cannot_schedule_posted_post	Post is already live	Create a new draft

Assets

Message	Meaning	Fix
mime_not_allowed: image/webp	MIME type isn’t allowed for the kind	Convert to an allowed type
unsupported_kind	Unknown asset kind	Use image, video, or document
inline_too_large_use_presign	Inline upload over 5 MB	Use request_asset_upload
too_large	File over the kind’s ceiling	Compress, or split the post
bytes_missing	Attaching before the PUT finished	Upload the bytes, then attach
too_many_images	More images than the platform allows	Detach some (9 LinkedIn, 4 X)
asset_not_found / post_not_found	Wrong id, or another studio’s	Re-check the ids
publishing_video_not_supported_yet	Video/document publishing isn’t wired	Detach it, or publish text and images

Access

Message	Meaning	Fix
forbidden	Tool needs owner or admin	Ask a studio admin to run it
unauthorized	No valid session	Reconnect the MCP server
No studio membership	The user belongs to no studio	Sign in to the web app once

Platform errors

When a platform rejects the post, its message is passed through:

• Permanent (platform 4xx that isn’t a rate limit) — the post is not published, and a scheduled post is marked failed without retrying.
• Transient (429 and 5xx) — a scheduled post retries with exponential backoff up to 5 attempts before failing.

For a failed post, read failureReason — it is prefixed with the platform, e.g. linkedin: ….