Errors

A DevHub error says what to fix. Fix the argument and call again. One error is never a reason to stop using DevHub for the rest of the session.

Message	What it means	What to do
sign in required (on every request)	the user’s session ended; the server stopped serving	tell the user to sign in to DevHub again. Do not retry in a loop
MCP tool "<name>" is disabled in Settings	the user switched the tool off	use another tool or ask the user to enable it in Settings > MCP Server > Allowed MCP tools
MCP tool "<name>" is not available: requires <permission>	the user’s Vartari plan does not include this area for agents, or not at the level the tool needs	do not retry. Tell the user which permission it names
MCP tool "<name>" is not enabled for this endpoint	this endpoint’s profile does not offer the tool	use a tool you were offered
Unknown tool	the name does not exist	take names from the tool list, not from memory
<area> is not configured or is not available	the feature is not set up in DevHub	tell the user; nothing to fix in the call

Message	What to do
A claim needs an owner	pass by to plan_claim or plan_renew
query is required	pass a non-empty query
workspaceId is required when saving a screenshot	pass workspaceId with save
wait must be seconds from 0 to 45	pass wait between 0 and 45
allowAgents must be true or false	pass a boolean
Request too large	send less in one call; split the content
a hash or text mismatch on file_edit, file_replace, vault_file_edit	read the file again and rebuild the edit from the new text
already exists on a create	the file is there. Read it; use file_replace or file_write if replacing is intended
a script is refused	npm_script_list shows what is declared. Only declared scripts run

Message	What to do
Vault not found or disabled	take vaultId from vault_list
Vault is not configured for MCP write access	the vault is read-only for MCP. Ask the user to allow writing, or write elsewhere
This note is in a knowledge folder: <problems>	the note fails the rules of that folder. Fix what the message lists and write again
knowledge_search returns nothing	a miss is not absence. vault_overview, then vault_files_search; knowledge_index_status, then knowledge_index_refresh

An agent started by DevHub works under narrower rules.

Message	What to do
This agent works only in its own repository. Use its workspaceId.	use the workspaceId of your own repository
This agent may use only its own repository's, project's and organization's vaults.	take a vaultId from vault_list
This plan is not for this agent's repository.	take plans from plan_ready
An agent cannot start itself. Start a different agent, or answer the task yourself.	answer the task, or start another agent
An agent cannot give another agent leave to start agents. Run it without allowAgents.	leave allowAgents out
An agent cannot close an investigation. …	say in your answer that it is ready to close

Message	What to do
No such agent on this endpoint. Call agent_list for the ones there are.	take agentId from agent_list
No persona "<id>" or No client "<id>"	agent_list shows the ones agent_create accepts
No such run	take runId from the RUNNING answer. A run’s answer lasts an hour
RUNNING <runId>	not an error. Call agent_run_status with wait

Message	What to do
a refused plan_claim	the refusal says why: someone holds the step, a gate is open, or a step in progress touches the same files. Call plan_ready and take another step
Step not closed: <reason>	the working tree did not merge. Resolve the conflict in the working tree, commit, call plan_close again
a refused plan_close	you are not the holder, or the step is not in a state that can close. Read the message; step_resume shows the state
refused plan_create	the id is taken. Choose another or omit it

• audit_list with tool and result shows the failed call: arguments, error, timing.
• audit_analyze shows repeated errors and slow tools.
• audit_summary shows the success rate over a window.

• Limits
• Troubleshooting