# wait_for_renders

Waits for new renders to arrive after a code change. Call this after modifying code to wait for HMR to complete and measure the resulting re-renders. Returns a summary of new renders received during the wait period.

Agent View of the PolicyLayer registry record for `wait_for_renders`. HTML page: https://policylayer.com/tools/0x1f320-why-did-you-render-mcp/wait-for-renders

## Facts

- Tool: `wait_for_renders`
- Server: Why Did You Render (`0x1f320/why-did-you-render-mcp`) — https://policylayer.com/tools/0x1f320-why-did-you-render-mcp.md
- Homepage: https://github.com/0x1f320/why-did-you-render-mcp
- Risk category: Execute (High risk)
- Registry record: grade F, identity unverified
- Server rate-limited: no
- Parameters: 0
- Recommended policy verdict: Rate-limited

## Example call (MCP tools/call, JSON-RPC 2.0)

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "wait_for_renders",
    "arguments": {}
  }
}
```

## Why wait_for_renders is rated High

This tool executes an external operation (waiting for and measuring React re-renders via HMR) triggered by code modifications. While it does not directly modify data or delete anything, it runs a process that observes and reports on effects of external code execution, fitting the Execute category.

From the tool's own definition: "'Waits for new renders to arrive after a code change' and 'Call this after modifying code' indicates the tool triggers and monitors external operations (HMR/Hot Module Replacement) whose effects depend on what code was modified, and 'measure the resulting…"

## Use case

AI agents invoke wait_for_renders to trigger actions in Why Did You Render. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call: builds kicked off, notifications sent, workflows started.

## Recommended policy (PolicyLayer)

Verdict: **Rate-limited**. Enforced by the PolicyLayer MCP gateway (https://policylayer.com/mcp-gateway) before a call reaches Why Did You Render:

```json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "wait_for_renders": {
      "limits": [
        {
          "counter": "wait_for_renders_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}
```

## Other tools on Why Did You Render (13)

- `clear_renders` — Destructive — https://policylayer.com/tools/0x1f320-why-did-you-render-mcp/clear-renders.md
- `delete_snapshot` — Destructive — https://policylayer.com/tools/0x1f320-why-did-you-render-mcp/delete-snapshot.md
- `pause_renders` — Execute — https://policylayer.com/tools/0x1f320-why-did-you-render-mcp/pause-renders.md
- `compare_snapshots` — Read — https://policylayer.com/tools/0x1f320-why-did-you-render-mcp/compare-snapshots.md
- `get_commits` — Read — https://policylayer.com/tools/0x1f320-why-did-you-render-mcp/get-commits.md
- `get_projects` — Read — https://policylayer.com/tools/0x1f320-why-did-you-render-mcp/get-projects.md
- `get_render_summary` — Read — https://policylayer.com/tools/0x1f320-why-did-you-render-mcp/get-render-summary.md
- `get_renders` — Read — https://policylayer.com/tools/0x1f320-why-did-you-render-mcp/get-renders.md
- `get_renders_by_commit` — Read — https://policylayer.com/tools/0x1f320-why-did-you-render-mcp/get-renders-by-commit.md
- `get_tracked_components` — Read — https://policylayer.com/tools/0x1f320-why-did-you-render-mcp/get-tracked-components.md
- `list_snapshots` — Read — https://policylayer.com/tools/0x1f320-why-did-you-render-mcp/list-snapshots.md
- `resume_renders` — Write — https://policylayer.com/tools/0x1f320-why-did-you-render-mcp/resume-renders.md
- `save_snapshot` — Write — https://policylayer.com/tools/0x1f320-why-did-you-render-mcp/save-snapshot.md

## For agents

This record is a snapshot. Live verdicts and the full registry:

- Check every server in your MCP config at once: `npx -y policylayer stack`
- Vet a server before you add it: install the mcp-precheck skill — `npx skills add https://policylayer.com` (skill text: https://policylayer.com/skill.md)
- Query the registry over MCP: endpoint `https://api.policylayer.com/mcp` — tools `check_mcp_server`, `check_mcp_stack`, `check_tool`, `search_registry`, `get_change_events`

---

Source: the PolicyLayer MCP registry — one continuously verified record per MCP server. Full record: https://policylayer.com/registry?q=0x1f320-why-did-you-render-mcp · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/0x1f320-why-did-you-render-mcp