Validate a candidate MyWallpaper addon manifest against the canonical JSON Schema (Draft 2019-09). Checks shape, required fields, enum values, and deny_unknown_fields. Does NOT check server-side business rules (entry path safety, domain allow-list regex, etc.).
Part of the Addon server.
Free to start. No card required.
AI agents call validate_manifest to retrieve information from Addon without modifying any data. This is common in research, monitoring, and reporting workflows where the agent needs context before taking action. Because read operations don't change state, they are generally safe to allow without restrictions -- but you may still want rate limits to control API costs.
Even though validate_manifest only reads data, uncontrolled read access can leak sensitive information or rack up API costs. An agent caught in a retry loop could make thousands of calls per minute. A rate limit gives you a safety net without blocking legitimate use.
Read-only tools are safe to allow by default. No rate limit needed unless you want to control costs.
{
"version": "1",
"default": "deny",
"tools": {
"validate_manifest": {}
}
}See the full Addon policy for all 14 tools.
These attack patterns abuse exactly the kind of access validate_manifest gives an agent. Each links to the full case and the policy that stops it:
Other read tools across the catalogue. The same approach applies to each: allow, with a rate cap to control cost.
Validate a candidate MyWallpaper addon manifest against the canonical JSON Schema (Draft 2019-09). Checks shape, required fields, enum values, and deny_unknown_fields. Does NOT check server-side business rules (entry path safety, domain allow-list regex, etc.).. It is categorised as a Read tool in the Addon MCP Server, which means it retrieves data without modifying state.
Register the Addon MCP server in PolicyLayer and add a rule for validate_manifest: 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 Addon. Nothing to install.
validate_manifest is a Read tool with low risk. Read-only tools are generally safe to allow by default.
Yes. Add a rate_limit block to the validate_manifest 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 validate_manifest. 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.
validate_manifest is provided by the Addon MCP server (@mywallpaper/addon-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 14 Addon tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
4,600+ MCP servers and 31,000+ tools scanned and risk-classified.