update_decision

SERVERMeridian SOURCE@meridianmcp/mcp

Medium RISK CLASS

Category Write

Parameters 101 required

Recommended Rate-limitedsee the rule below

Registry record Grade F, identity unverified Pull the record →

This record as markdown: /tools/io-github-ajc3xc-meridian/update-decision.md

WHAT IT DOES

What update_decision does on Meridian

AI agents use update_decision to create or update resources in Meridian, usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Meridian environment.

Parameter	Type	Required	Description
`body`	string	—
`title`	string	—
`status`	string	—
`category`	string	—
`new_body`	string	—
`priority`	string	—	Change ordering/weight (urgent \| normal \| low).
`new_title`	string	—
`assumption`	string	—	Set/replace the decision's underlying assumption text.
`decision_id`	string	Yes
`assumption_status`	string	—	Stamp the assumption's validation state. Usually set via the validate_assumption tool, which also fires HITL on invalidation.

Parameters from the server's own tool schema.

RISK

Why update_decision is rated Medium

This tool creates and modifies decision records in a persistent system. While it maintains audit trails (edit_log) making changes traceable and partially reversible through version history, the core capability is Write (creates new rows, patches existing records). It is not Destructive because old records are retained with back-links and marked as superseded rather than deleted.

From the tool's definition Tool description explicitly states 'Patch a pinned decision' and describes modification operations: 'atomically supersede (creates a new active row, marks old as superseded)', 'patches body/title/category/status/priority in place', and maintains append-only…

Risk signalsAccepts raw HTML/template content (body) · High parameter count (10 properties)

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs update_decision safely

PolicyLayer is an MCP gateway: it sits between your AI agents and Meridian, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For update_decision, this is the rule to start with:

update_decision Rate-limited

update_decision 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.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "update_decision": {
      "limits": [
        {
          "counter": "update_decision_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

LIMIT THIS TOOL → Instant setup, no code required.

The button opens the PolicyLayer dashboard: create your workspace, connect Meridian, apply this rule, and every update_decision call is checked against it from then on.

FAQ

Questions about update_decision

What does the update_decision tool do? +

[SUPPORT] Patch a pinned decision. Pass new_title + new_body to atomically supersede (creates a new active row, marks old as superseded with back-link). Otherwise patches body/title/category/status/priority in place. Editing the body appends the previous body to the append-only edit_log (read it back via get_pinned_decisions). Persistent-state disclosure: on hosted Meridian, supplied text and project/session metadata are sent to and stored in Meridian's service; self-hosted deployments keep them in the configured local SQLite/Postgres database. This data is visible in the dashboard/API and later project context or handoffs. Delete individual tasks, notes, or decisions where supported, or delete the project/account using the documented controls. Do not include secrets. It is categorised as a Write tool in the Meridian MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

What parameters does update_decision accept? +

update_decision accepts 10 parameters: body, title, status, category, new_body, priority, new_title, assumption, decision_id, assumption_status. Required: decision_id. The full parameter table on this page comes from the server's own tool schema.

How do I enforce a policy on update_decision? +

Register the Meridian MCP server in PolicyLayer and add a rule for update_decision: 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 Meridian. Nothing to install.

What risk level is update_decision? +

update_decision is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit update_decision? +

Yes. Add a rate_limit block to the update_decision 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.

How do I block update_decision completely? +

Set action: deny in the PolicyLayer policy for update_decision. 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.

What MCP server provides update_decision? +

update_decision is provided by the Meridian MCP server (@meridianmcp/mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

KEEP EXPLORING

More on Meridian, and thousands of servers like it.

This server

All 175 Meridian tools →

Across the catalogue

aroflo_create_or_update_record on AroFlo MCP →team_manager_emit_decision on Team Manager MCP → The MCP Attack Database →

Guides

Govern customer-ops agents →Argument validation →Scoped token →