A tool's grant covers the machine-addressed subject, and a credential names the seats its module claims (hq ADR 0159)

`invokes: [<module>.<tool>]` now grants `mesh.mod.<module>.tool.<tool>` and the same with the
machine as its last token, which is how a call reaches one machine's instance. The broker
credential the mesh writes carries `claims`: each seat the module claims, its scope, and the verbs
the seat promises, so the runtime serves them on the seat's subjects; the holder's grant, composed
from the holding, is what admits the subscription.

internal/broker/nats.go

@@ -660,7 +660,10 @@ func invokedSubjects(invokes []string) ([]string, error) {
 			return nil, fmt.Errorf(
 				"%q does not name a tool: one invokes <module>.<tool>, seat:<seat>.<verb>, or * for every one", t)
 		}
-		out = append(out, "mesh.mod."+module+".tool."+tool)
+		// Both ways a module's tool is addressed (novox/hq ADR 0159): to whichever instance
+		// answers, and to the instance on one machine, which is the same subject with the machine
+		// as its last token.
+		out = append(out, "mesh.mod."+module+".tool."+tool, "mesh.mod."+module+".tool."+tool+".*")
 	}
 	return out, nil
 }