check_compatibility
AI agents call check_compatibility to retrieve information from Glyphs without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
The tool's name and context suggest it performs a compatibility check, which typically involves reading font data to assess compatibility without modifying it. The lack of a description lowers confidence, but the pattern of sibling tools being non-destructive analysis functions supports a Read classification. No evidence suggests this performs writes, deletes, or executes code.
From the tool's definition Tool named 'check_compatibility' with no description provided. Sibling tools are primarily analysis and auditing functions (analyze_kerning, check_overshoots, etc.), which are read-only. The name suggests verification/checking rather than modification.
Documented attack patterns abuse exactly the kind of access check_compatibility gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Glyphs, and nothing reaches the server without passing your rules. This is the rule we recommend for check_compatibility:
{
"version": "1",
"default": "deny",
"tools": {
"check_compatibility": {}
}
}check_compatibility is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.
Free to start. No card required.
check_compatibility. It is categorised as a Read tool in the Glyphs MCP Server, which means it retrieves data without modifying state.
Register the Glyphs MCP server in PolicyLayer and add a rule for check_compatibility: 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 Glyphs. Nothing to install.
check_compatibility 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 check_compatibility 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 check_compatibility. 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.
check_compatibility is provided by the Glyphs MCP server (nmassi/glyphs-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Glyphs, 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.
41 Glyphs tools catalogued and risk-classified — across an index of 43,000+ MCP servers.