AI agents use defer_phase to create or update resources in Codevira MCP — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Codevira MCP environment.
This tool modifies the state of a phase by relocating it from the upcoming list to a deferred list. This is a reversible write operation (the phase can presumably be moved back), not a deletion or execution of code. Misuse could disrupt project planning and AI agent workflows, warranting medium severity.
From the tool's definition Move an upcoming phase to the deferred list
Documented attack patterns abuse exactly the kind of access defer_phase gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Codevira MCP, and nothing reaches the server without passing your rules. This is the rule we recommend for defer_phase:
{
"version": "1",
"default": "deny",
"tools": {
"defer_phase": {
"limits": [
{
"counter": "defer_phase_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}defer_phase stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.
Free to start. No card required.
Move an upcoming phase to the deferred list. It is categorised as a Write tool in the Codevira MCP MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Codevira MCP server in PolicyLayer and add a rule for defer_phase: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches Codevira MCP. Nothing to install.
defer_phase is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.
Yes. Add a rate_limit block to the defer_phase rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.
Set action: deny in the PolicyLayer policy for defer_phase. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.
defer_phase is provided by the Codevira MCP server (sachinshelke/codevira). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Codevira MCP, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
Free to start. No card required.
48 Codevira MCP tools catalogued and risk-classified — across an index of 43,000+ MCP servers.