Kuro

Cancel workflow run

cancel_workflow_run

DestructiveIdempotent

Cancel a workflow run.

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "run_id": "<run_id>"
    },
    "name": "cancel_workflow_run"
  }
}

Input Schema

Name	Required	Description	Default
`run_id`	Yes

Output Schema

Name	Required	Description	Default
`run`	No
`count`	No
`steps`	No
`credits`	No
`fan_outs`	No
`recovery`	No
`checkpoint`	No
`storyboard`	No
`conditional`	No
`generations`	No
`review_hash`	No
`unit_credits`	No
`analysis_credits`	No
`checkpoint_error`	No

Schema Changelog

Changes observed during successful MCP inspections.

Changed4 schema fields changedNov 4, 2026

changedOutput schema / properties / generations / items / additionalProperties
```
Previous value: -{}New value: +false
```
addedOutput schema / properties / generations / items / description
```
Added value: +"One image, clip, voice-over or piece of music."
```

addedOutput schema / properties / generations / items / properties

Added value: +{
+  "app_url": {
+    "description": "Opens it in the app.",
+    "format": "uri",
+    "type": "string"
+  },
+  "aspect_ratio": {
+    "description": "Null for audio.",
+    "type": [
+      "string",
+      "null"
+    ]
+  },
+  "caption_style": {
+    "anyOf": [
+      {
+        "additionalProperties": false,
+        "properties": {
+          "anchor": {
+            "default": "bottom",
+            "enum": [
+              "top",
+              "bottom"
+            ],
+            "type": "string"
+          },
+          "border": {
+            "anyOf": [
+              {
+                "additionalProperties": false,
+                "properties": {
+                  "color": {
+                    "$ref": "#/properties/generations/items/properties/caption_style/anyOf/0/properties/color",
+                    "default": "#000000"
+                  },
+                  "kind": {
+                    "const": "outline",
+                    "type": "string"
+                  },
+                  "scale": {
+                    "default": 0.049,
+                    "maximum": 0.3,
+                    "minimum": 0,
+                    "type": "number"
+                  },
+                  "shadow_scale": {
+                    "default": 0.012,
+                    "maximum": 0.3,
+                    "minimum": 0,
+                    "type": "number"
+                  }
+                },
+                "required": [
+                  "kind"
+                ],
+                "type": "object"
+              },
+              {
+                "additionalProperties": false,
+                "properties": {
+                  "color": {
+                    "$ref": "#/properties/generations/items/properties/caption_style/anyOf/0/properties/color",
+                    "default": "#000000"
+                  },
+                  "kind": {
+                    "const": "plate",
+                    "type": "string"
+                  },
+                  "pad_scale": {
+                    "default": 0.025,
+                    "maximum": 0.3,
+                    "minimum": 0,
+                    "type": "number"
+                  }
+                },
+                "required": [
+                  "kind"
+                ],
+                "type": "object"
+              }
+            ],
+            "default": {
+              "color": "#000000",
+              "kind": "outline",
+              "scale": 0.049,
+              "shadow_scale": 0.012
+            }
+          },
+          "casing": {
+            "default": "upper",
+            "enum": [
+              "none",
+              "upper"
+            ],
+            "type": "string"
+          },
+          "color": {
+            "default": "#FFFFFF",
+            "pattern": "^#[0-9a-fA-F]{6}(?:[0-9a-fA-F]{2})?$",
+            "type": "string"
+          },
+          "font_id": {
+            "default": "noto-sans",
+            "enum": [
+              "inter",
+              "montserrat",
+              "oswald",
+              "archivo-black",
+              "noto-sans",
+              "tiktok-sans"
+            ],
+            "type": "string"
+          },
+          "font_scale": {
+            "default": 0.075,
+            "maximum": 0.2,
+            "minimum": 0.02,
+            "type": "number"
+          },
+          "font_weight": {
+            "default": 700,
+            "maximum": 900,
+            "minimum": 100,
+            "multipleOf": 100,
+            "type": "integer"
+          },
+          "grouping": {
+            "additionalProperties": false,
+            "default": {
+              "gap_seconds": null,
+              "max_chars": null,
+              "max_lines": 2,
+              "max_words": null,
+              "unit": "phrase"
+            },
+            "properties": {
+              "gap_seconds": {
+                "anyOf": [
+                  {
+                    "maximum": 4,
+                    "minimum": 0,
+                    "type": "number"
+                  },
+                  {
+                    "type": "null"
+                  }
+                ],
+                "default": null
+              },
+              "max_chars": {
+                "anyOf": [
+                  {
+                    "maximum": 160,
+                    "minimum": 8,
+                    "type": "integer"
+                  },
+                  {
+                    "type": "null"
+                  }
+                ],
+                "default": null
+              },
+              "max_lines": {
+                "default": 2,
+                "enum": [
+                  1,
+                  2
+                ],
+                "type": "number"
+              },
+              "max_words": {
+                "anyOf": [
+                  {
+                    "maximum": 24,
+                    "minimum": 1,
+                    "type": "integer"
+                  },
+                  {
+                    "type": "null"
+                  }
+                ],
+                "default": null
+              },
+              "unit": {
+                "default": "phrase",
+                "enum": [
+                  "word",
+                  "phrase",
+                  "sentence"
+                ],
+                "type": "string"
+              }
+            },
+            "type": "object"
+          },
+          "highlight": {
+            "default": "active_word",
+            "enum": [
+              "none",
+              "active_word",
+              "karaoke"
+            ],
+            "type": "string"
+          },
+          "highlight_color": {
+            "$ref": "#/properties/generations/items/properties/caption_style/anyOf/0/properties/color",
+            "default": "#FFD700"
+          },
+          "italic": {
+            "default": false,
+            "type": "boolean"
+          },
+          "margin_h": {
+            "default": 0.06,
+            "maximum": 0.4,
+            "minimum": 0,
+            "type": "number"
+          },
+          "margin_v": {
+            "anyOf": [
+              {
+                "const": "auto",
+                "type": "string"
+              },
+              {
+                "maximum": 0.45,
+                "minimum": 0,
+                "type": "number"
+              }
+            ],
+            "default": "auto"
+          },
+          "schema_version": {
+            "const": "1.0",
+            "default": "1.0",
+            "type": "string"
+          }
+        },
+        "type": "object"
+      },
+      {
+        "type": "null"
+      }
+    ]
+  },
+  "created_at": {
+    "format": "date-time",
+    "type": "string"
+  },
+  "credits": {
+    "description": "Credits charged. Zero when your own provider key or the free allowance paid.",
+    "type": [
+      "number",
+      "null"
+    ]
+  },
+  "error": {
+    "description": "Why it failed. Null otherwise.",
+    "type": [
+      "string",
+      "null"
+    ]
+  },
+  "id": {
+    "format": "uuid",
+    "type": "string"
+  },
+  "model": {
+    "description": "The model id it was made with (`GET /v1/models`).",
+    "type": "string"
+  },
+  "object": {
+    "const": "generation",
+    "type": "string"
+  },
+  "output_url": {
+    "anyOf": [
+      {
+        "format": "uri",
+        "type": "string"
+      },
+      {
+        "type": "null"
+      }
+    ],
+    "description": "The finished file, once `ready`. A signed link that works for about an hour; read the generation again for a fresh one."
+  },
+  "paid_by": {
+    "description": "Who paid: \"credits\", \"house\" (the free allowance), \"server\" (a server that charges nothing), or the vendor of your own key (\"replicate\", \"fal\", …).",
+    "type": [
+      "string",
+      "null"
+    ]
+  },
+  "prompt": {
+    "type": "string"
+  },
+  "ready_in_seconds": {
+    "description": "Roughly how long an unfinished generation has left; 0 means past its usual time.",
+    "type": [
+      "number",
+      "null"
+    ]
+  },
+  "recipe_id": {
+    "anyOf": [
+      {
+        "$ref": "#/properties/generations/items/properties/id"
+      },
+      {
+        "type": "null"
+      }
+    ],
+    "description": "The recipe it was made with, if any."
+  },
+  "refined_from": {
+    "anyOf": [
+      {
+        "format": "uuid",
+        "type": "string"
+      },
+      {
+        "type": "null"
+      }
+    ]
+  },
+  "stalled": {
+    "type": "boolean"
+  },
+  "status": {
+    "description": "`ready` and `failed` are final.",
+    "enum": [
+      "queued",
+      "generating",
+      "ready",
+      "failed"
+    ],
+    "type": "string"
+  },
+  "thumbnail_url": {
+    "anyOf": [
+      {
+        "$ref": "#/properties/generations/items/properties/output_url/anyOf/0"
+      },
+      {
+        "type": "null"
+      }
+    ],
+    "description": "A small still of the result, for a grid. Null for audio and while it works."
+  },
+  "type": {
+    "description": "What was made. New values may be added; treat an unknown one as opaque.",
+    "enum": [
+      "image",
+      "clip",
+      "voiceover",
+      "music",
+      "tool"
+    ],
+    "type": "string"
+  },
+  "vendor_phase": {
+    "anyOf": [
+      {
+        "enum": [
+          "queued",
+          "running"
+        ],
+        "type": "string"
+      },
+      {
+        "type": "null"
+      }
+    ]
+  }
+}

addedOutput schema / properties / generations / items / required

Added value: +[
+  "object",
+  "id",
+  "type",
+  "status",
+  "model",
+  "prompt",
+  "aspect_ratio",
+  "output_url",
+  "thumbnail_url",
+  "credits",
+  "paid_by",
+  "error",
+  "ready_in_seconds",
+  "recipe_id",
+  "created_at",
+  "app_url",
+  "refined_from",
+  "caption_style",
+  "vendor_phase",
+  "stalled"
+]

First observedOct 15, 2026

TDQS

C2.1/5.0

Behavior2/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare destructiveHint=true, idempotentHint=true, readOnlyHint=false, and openWorldHint=false, so the safety profile is fully carried by structured fields. The description adds no behavioral context beyond them: nothing about what happens to in-flight steps, partial outputs, whether cancellation is reversible, or auth/permission requirements. There is no contradiction with the annotations, but no value added either.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness3/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The one-sentence description contains no waste and is trivially front-loaded, but that is because it says nothing at all. Conciseness is satisfied at the cost of substantiveness, which is under-specification rather than good economy.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness2/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

An output schema exists, so return values need not be described, and annotations cover the destructive/idempotent profile. Still, for a destructive mutation on an external workflow run, the description should at minimum say what state the run is left in and how it relates to resume/retry; that gap remains unfilled.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters2/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The single required parameter run_id has 0% schema description coverage, so the schema supplies only a uuid format with no meaning attached. The description does not compensate by explaining whether run_id is a workflow-run identifier returned by list_workflow_runs or start_recipe_run, nor what an invalid or already-completed run id yields.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose2/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description restates the tool name and title verbatim ("Cancel a workflow run") without adding scope, target, or effect detail. An agent learns nothing it could not already infer from the name, and no distinction from siblings such as resume_workflow_run, retry_workflow_run, rewind_workflow_run, or cancel_storyboard_work is drawn.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines2/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

No when-to-use guidance is given, and the presence of four closely related workflow-lifecycle tools (resume, retry, rewind, get) makes routing ambiguous. The description neither names an alternative nor states the condition that should select this tool, leaving the agent to guess from names alone.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

All Kuro tools Inspect

Try in Browser

One endpoint for every MCP toolRayrun runs every MCP server behind one URL and holds the credentials. Each call is decided per client, tool, and argument, then recorded.ray.runAd

Glama MCP Gateway

Add one secure layer between your agents and this server.

Resources

Need Help?