pin_decision

SERVERMeridian SOURCE@meridianmcp/mcp

Medium RISK CLASS

Category Write

Parameters 72 required

Recommended Rate-limitedsee the rule below

Registry record Grade D, identity unverified Pull the record →

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

WHAT IT DOES

What pin_decision does on Meridian

AI agents use pin_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	Yes
`title`	string	Yes
`category`	string	—
`priority`	string	—	urgent decisions sort first and are weighted higher in start_session / generate_handoff context. Default normal.
`assumption`	string	—	Optional unverified assumption this decision rests on. Recorded with status 'unvalidated' and surfaced in get_planning_brief until validate_assumption confirms
`project_id`	string	—
`project_name`	string	—	Project name — an alternative to project_id; resolved to the id internally. project_id wins if both are given.

Parameters from the server's own tool schema.

RISK

Why pin_decision is rated Medium

An AI agent can call pin_decision faster than any human can review: one bad instruction and it creates or modifies resources in Meridian by the hundred, each call as confident as the last.

Risk signalsAccepts raw HTML/template content (body)

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs pin_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 pin_decision, this is the rule to start with:

pin_decision Rate-limited

pin_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": {
    "pin_decision": {
      "limits": [
        {
          "counter": "pin_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 pin_decision call is checked against it from then on.

FAQ

Questions about pin_decision

What does the pin_decision tool do? +

[SUPPORT] Create a pinned decision (editable constitution row). Use for the current authoritative truth that supersedes earlier statements. category is free-text; suggested values: STRATEGIC, COMPETITIVE, TECHNICAL, TACTICAL, BUSINESS, PRODUCT, ARCHITECTURAL. Persistent-state disclosure: on hosted Meridian, supplied text and project/session metadata -- including task log entries, pinned decisions, sprint items, notes, handoff/goal state, and HITL queue items -- are sent to and stored in Meridian's service, in an isolated per-tenant Postgres database (Neon); self-hosted deployments keep the same categories in the configured local SQLite/Postgres database. This data is visible in the dashboard and API, and may resurface in later project context or handoffs. Notes and pinned decisions can be deleted individually; task log entries and sprint items can be deleted via the dashboard/API (not exposed as an agent-facing tool); HITL queue items and handoff state have no per-record delete. Full removal of any of this data is available via project or account deletion, 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 pin_decision accept? +

pin_decision accepts 7 parameters: body, title, category, priority, assumption, project_id, project_name. Required: body, title. The full parameter table on this page comes from the server's own tool schema.

How do I enforce a policy on pin_decision? +

Register the Meridian MCP server in PolicyLayer and add a rule for pin_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 pin_decision? +

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

Can I rate-limit pin_decision? +

Yes. Add a rate_limit block to the pin_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 pin_decision completely? +

Set action: deny in the PolicyLayer policy for pin_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 pin_decision? +

pin_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 235 Meridian tools →

Across the catalogue

team_manager_emit_decision on Team Manager MCP → The MCP Attack Database →

Guides

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