mcphost

host.tool_call

Invoke a tool this tenant has already published, by its local name -- the same real, metered call as calling it directly by its namespaced name (.), for a session that has no way to see its own namespaced tool name yet. Unlike host.tool_test, this counts toward host.usage and appears in host.tool_logs. Pass async: true for a tool that needs more than the call deadline: returns {run_id, status: "queued"} immediately instead of running inline -- see host.runs.get/wait. Pass version to pin the call to one of host.tool_history's versions instead of whichever is current.

Input Schema

TableJSON Schema

Name	Required	Description
`args`	Yes	Arguments to pass, validated against the tool's own args_schema.
`name`	Yes	Local name of the tool to invoke.
`async`	No	Run as a job instead of inline: returns {run_id, status} within ~50ms under the plan's job_max_s deadline; default false.
`budget`	No	Lowers this call's budget below the plan default: any subset of max_child_calls, max_est_tokens, max_tool_latency_ms, max_wall_ms. A value above the plan's own ceiling is a validation error naming it; see host.runs.get's progress.budget.
`dry_run`	No	Ask instead of call: runs every admission check the real call runs, dispatches nothing, writes no call row, and returns {fits, units, remaining, refusal}; same as host.estimate. Default false.
`version`	No	Pin the call to this version instead of whichever is current; see host.tool_history. An unknown version is an argument error.
`tenant_key`	No	The key `signup` returned. Optional on the connection that ran signup (or host.redeem): that connection is already bound to the tenant it created, so later calls on it need no tenant_key. On a connection with no Authorization: Bearer header and no prior signup, omitting it implicitly signs that connection up as a brand-new tenant and runs this call as it -- see host.whoami's source field. When both a header and this argument are present, the header wins.

Output Schema

TableJSON Schema

Name	Required	Description	Default
`id`	No
`ok`	No
`tz`	No
`v1`	No
`msg`	No
`url`	No
`args`	No
`body`	No
`kind`	No
`name`	No
`next`	No
`rows`	No
`text`	No
`tool`	No
`count`	No
`steps`	No
`preset`	No
`result`	No
`run_id`	No
`status`	No
`verify`	No
`changed`	No
`columns`	No
`created`	No
`doubled`	No
`enabled`	No
`headers`	No
`payload`	No
`schedule`	No
`next_unix`	No
`checked_at`	No
`onboarding`	No
`unverified`	No
`client_tool`	No
`https_proxy`	No
`last_run_id`	No
`last_status`	No
`created_unix`	No
`failed_steps`	No
`forwarded_to`	No
`welcome_back`	No
`dedupe_header`	No
`last_fired_unix`	No

Schema Changelog

Changes observed during successful MCP inspections.

Changed84 schema fields changedOct 16, 2026
- changedOutput schema / properties / args / type
```
Previous value: -"object"New value: +[
+  "object",
+  "null"
+]
```
- changedOutput schema / properties / body / properties / ok / type
```
Previous value: -"boolean"New value: +[
+  "boolean",
+  "null"
+]
```
- changedOutput schema / properties / body / properties / pong / type
```
Previous value: -"boolean"New value: +[
+  "boolean",
+  "null"
+]
```
- changedOutput schema / properties / body / type
```
Previous value: -"object"New value: +[
+  "object",
+  "null"
+]
```
- changedOutput schema / properties / changed / type
```
Previous value: -"array"New value: +[
+  "array",
+  "null"
+]
```
- changedOutput schema / properties / checked_at / type
```
Previous value: -"integer"New value: +[
+  "integer",
+  "null"
+]
```
- changedOutput schema / properties / client_tool / type
```
Previous value: -"string"New value: +[
+  "string",
+  "null"
+]
```
- changedOutput schema / properties / columns / type
```
Previous value: -"array"New value: +[
+  "array",
+  "null"
+]
```
- changedOutput schema / properties / count / type
```
Previous value: -"integer"New value: +[
+  "integer",
+  "null"
+]
```
- changedOutput schema / properties / created / type
```
Previous value: -"boolean"New value: +[
+  "boolean",
+  "null"
+]
```
- changedOutput schema / properties / created_unix / type
```
Previous value: -"integer"New value: +[
+  "integer",
+  "null"
+]
```
- removedOutput schema / properties / dedupe_header / type
```
Removed value: -"null"
```
- changedOutput schema / properties / doubled / type
```
Previous value: -"integer"New value: +[
+  "integer",
+  "null"
+]
```
- changedOutput schema / properties / enabled / type
```
Previous value: -"boolean"New value: +[
+  "boolean",
+  "null"
+]
```
- changedOutput schema / properties / failed_steps / type
```
Previous value: -"array"New value: +[
+  "array",
+  "null"
+]
```
- changedOutput schema / properties / forwarded_to / type
```
Previous value: -"string"New value: +[
+  "string",
+  "null"
+]
```
- changedOutput schema / properties / headers / properties / content-type / type
```
Previous value: -"string"New value: +[
+  "string",
+  "null"
+]
```
- changedOutput schema / properties / headers / type
```
Previous value: -"object"New value: +[
+  "object",
+  "null"
+]
```
- changedOutput schema / properties / https_proxy / type
```
Previous value: -"string"New value: +[
+  "string",
+  "null"
+]
```
- changedOutput schema / properties / id / type
```
Previous value: -"string"New value: +[
+  "string",
+  "null"
+]
```
- changedOutput schema / properties / kind / type
```
Previous value: -"string"New value: +[
+  "string",
+  "null"
+]
```
- removedOutput schema / properties / last_fired_unix / type
```
Removed value: -"null"
```
- removedOutput schema / properties / last_run_id / type
```
Removed value: -"null"
```
- removedOutput schema / properties / last_status / type
```
Removed value: -"null"
```
- changedOutput schema / properties / msg / type
```
Previous value: -"string"New value: +[
+  "string",
+  "null"
+]
```
- changedOutput schema / properties / name / type
```
Previous value: -"string"New value: +[
+  "string",
+  "null"
+]
```
- changedOutput schema / properties / next / properties / tool / type
```
Previous value: -"string"New value: +[
+  "string",
+  "null"
+]
```
- changedOutput schema / properties / next / properties / why / type
```
Previous value: -"string"New value: +[
+  "string",
+  "null"
+]
```
- changedOutput schema / properties / next / type
```
Previous value: -"object"New value: +[
+  "object",
+  "null"
+]
```
- changedOutput schema / properties / next_unix / type
```
Previous value: -"integer"New value: +[
+  "integer",
+  "null"
+]
```
- changedOutput schema / properties / ok / type
```
Previous value: -"boolean"New value: +[
+  "boolean",
+  "null"
+]
```
- changedOutput schema / properties / onboarding / properties / claim_url / type
```
Previous value: -"string"New value: +[
+  "string",
+  "null"
+]
```
- changedOutput schema / properties / onboarding / properties / invited_by / type
```
Previous value: -"string"New value: +[
+  "string",
+  "null"
+]
```
- changedOutput schema / properties / onboarding / properties / shared_tools / type
```
Previous value: -"array"New value: +[
+  "array",
+  "null"
+]
```
- changedOutput schema / properties / onboarding / properties / tenant / type
```
Previous value: -"string"New value: +[
+  "string",
+  "null"
+]
```
- changedOutput schema / properties / onboarding / properties / url / type
```
Previous value: -"string"New value: +[
+  "string",
+  "null"
+]
```
- changedOutput schema / properties / onboarding / type
```
Previous value: -"object"New value: +[
+  "object",
+  "null"
+]
```
- changedOutput schema / properties / payload / properties / ok / type
```
Previous value: -"boolean"New value: +[
+  "boolean",
+  "null"
+]
```
- changedOutput schema / properties / payload / properties / pong / type
```
Previous value: -"boolean"New value: +[
+  "boolean",
+  "null"
+]
```
- changedOutput schema / properties / payload / type
```
Previous value: -"object"New value: +[
+  "object",
+  "null"
+]
```
- removedOutput schema / properties / preset / type
```
Removed value: -"null"
```
- changedOutput schema / properties / result / properties / region / type
```
Previous value: -"string"New value: +[
+  "string",
+  "null"
+]
```
- changedOutput schema / properties / result / properties / rows / type
```
Previous value: -"string"New value: +[
+  "string",
+  "null"
+]
```
- changedOutput schema / properties / result / type
```
Previous value: -"object"New value: +[
+  "object",
+  "null"
+]
```
- changedOutput schema / properties / rows / items / properties / body / properties / id / type
```
Previous value: -"string"New value: +[
+  "string",
+  "null"
+]
```
- changedOutput schema / properties / rows / items / properties / body / type
```
Previous value: -"object"New value: +[
+  "object",
+  "null"
+]
```
- changedOutput schema / properties / rows / items / properties / checked_at / type
```
Previous value: -"integer"New value: +[
+  "integer",
+  "null"
+]
```
- removedOutput schema / properties / rows / items / properties / delivery_id / type
```
Removed value: -"null"
```
- changedOutput schema / properties / rows / items / properties / id / type
```
Previous value: -"string"New value: +[
+  "string",
+  "null"
+]
```
- changedOutput schema / properties / rows / items / properties / latency_ms / type
```
Previous value: -"integer"New value: +[
+  "integer",
+  "null"
+]
```
- changedOutput schema / properties / rows / items / properties / ok / type
```
Previous value: -"boolean"New value: +[
+  "boolean",
+  "null"
+]
```
- changedOutput schema / properties / rows / items / properties / received_at / type
```
Previous value: -"integer"New value: +[
+  "integer",
+  "null"
+]
```
- changedOutput schema / properties / rows / items / properties / status / type
```
Previous value: -"string"New value: +[
+  "string",
+  "null"
+]
```
- changedOutput schema / properties / rows / items / properties / url / type
```
Previous value: -"string"New value: +[
+  "string",
+  "null"
+]
```
- changedOutput schema / properties / rows / type
```
Previous value: -"array"New value: +[
+  "array",
+  "null"
+]
```
- changedOutput schema / properties / run_id / type
```
Previous value: -"string"New value: +[
+  "string",
+  "null"
+]
```
- changedOutput schema / properties / schedule / type
```
Previous value: -"string"New value: +[
+  "string",
+  "null"
+]
```
- changedOutput schema / properties / status / type
```
Previous value: -[
-  "string",
-  "integer"
-]New value: +[
+  "string",
+  "integer",
+  "null"
+]
```
- changedOutput schema / properties / steps / items / properties / result / properties / region / type
```
Previous value: -"string"New value: +[
+  "string",
+  "null"
+]
```
- changedOutput schema / properties / steps / items / properties / result / properties / rows / type
```
Previous value: -"string"New value: +[
+  "string",
+  "null"
+]
```
- changedOutput schema / properties / steps / items / properties / result / properties / url / type
```
Previous value: -"string"New value: +[
+  "string",
+  "null"
+]
```
- changedOutput schema / properties / steps / items / properties / result / type
```
Previous value: -"object"New value: +[
+  "object",
+  "null"
+]
```
- changedOutput schema / properties / steps / items / properties / status / type
```
Previous value: -"string"New value: +[
+  "string",
+  "null"
+]
```
- changedOutput schema / properties / steps / items / properties / step / type
```
Previous value: -"integer"New value: +[
+  "integer",
+  "null"
+]
```
- changedOutput schema / properties / steps / items / properties / tool / type
```
Previous value: -"string"New value: +[
+  "string",
+  "null"
+]
```
- changedOutput schema / properties / steps / type
```
Previous value: -"array"New value: +[
+  "array",
+  "null"
+]
```
- changedOutput schema / properties / text / type
```
Previous value: -"string"New value: +[
+  "string",
+  "null"
+]
```
- changedOutput schema / properties / tool / type
```
Previous value: -"string"New value: +[
+  "string",
+  "null"
+]
```
- removedOutput schema / properties / tz / type
```
Removed value: -"null"
```
- changedOutput schema / properties / unverified / type
```
Previous value: -"boolean"New value: +[
+  "boolean",
+  "null"
+]
```
- changedOutput schema / properties / url / type
```
Previous value: -"string"New value: +[
+  "string",
+  "null"
+]
```
- changedOutput schema / properties / v1 / type
```
Previous value: -"string"New value: +[
+  "string",
+  "null"
+]
```
- changedOutput schema / properties / verify / properties / allow_unverified / type
```
Previous value: -"boolean"New value: +[
+  "boolean",
+  "null"
+]
```
- changedOutput schema / properties / verify / properties / scheme / type
```
Previous value: -"string"New value: +[
+  "string",
+  "null"
+]
```
- changedOutput schema / properties / verify / type
```
Previous value: -"object"New value: +[
+  "object",
+  "null"
+]
```
- removedOutput schema / properties / welcome_back / properties / last_note / type
```
Removed value: -"null"
```
- changedOutput schema / properties / welcome_back / properties / last_seen / type
```
Previous value: -"string"New value: +[
+  "string",
+  "null"
+]
```
- changedOutput schema / properties / welcome_back / properties / notes / type
```
Previous value: -"integer"New value: +[
+  "integer",
+  "null"
+]
```
- changedOutput schema / properties / welcome_back / properties / since_you_left / properties / calls / type
```
Previous value: -"integer"New value: +[
+  "integer",
+  "null"
+]
```
- changedOutput schema / properties / welcome_back / properties / since_you_left / properties / days / type
```
Previous value: -"integer"New value: +[
+  "integer",
+  "null"
+]
```
- changedOutput schema / properties / welcome_back / properties / since_you_left / properties / inbox / type
```
Previous value: -"integer"New value: +[
+  "integer",
+  "null"
+]
```
- changedOutput schema / properties / welcome_back / properties / since_you_left / properties / runs / type
```
Previous value: -"integer"New value: +[
+  "integer",
+  "null"
+]
```
- changedOutput schema / properties / welcome_back / properties / since_you_left / type
```
Previous value: -"object"New value: +[
+  "object",
+  "null"
+]
```
- changedOutput schema / properties / welcome_back / type
```
Previous value: -"object"New value: +[
+  "object",
+  "null"
+]
```

Changed1 schema field changedOct 12, 2026

changedOutput schema / (root)

Previous value: -nullNew value: +{
+  "properties": {
+    "args": {
+      "properties": {},
+      "type": "object"
+    },
+    "body": {
+      "properties": {
+        "ok": {
+          "type": "boolean"
+        },
+        "pong": {
+          "type": "boolean"
+        }
+      },
+      "type": "object"
+    },
+    "changed": {
+      "type": "array"
+    },
+    "checked_at": {
+      "type": "integer"
+    },
+    "client_tool": {
+      "type": "string"
+    },
+    "columns": {
+      "items": {
+        "type": "string"
+      },
+      "type": "array"
+    },
+    "count": {
+      "type": "integer"
+    },
+    "created": {
+      "type": "boolean"
+    },
+    "created_unix": {
+      "type": "integer"
+    },
+    "dedupe_header": {
+      "type": "null"
+    },
+    "doubled": {
+      "type": "integer"
+    },
+    "enabled": {
+      "type": "boolean"
+    },
+    "failed_steps": {
+      "type": "array"
+    },
+    "forwarded_to": {
+      "type": "string"
+    },
+    "headers": {
+      "properties": {
+        "content-type": {
+          "type": "string"
+        }
+      },
+      "type": "object"
+    },
+    "https_proxy": {
+      "type": "string"
+    },
+    "id": {
+      "type": "string"
+    },
+    "kind": {
+      "type": "string"
+    },
+    "last_fired_unix": {
+      "type": "null"
+    },
+    "last_run_id": {
+      "type": "null"
+    },
+    "last_status": {
+      "type": "null"
+    },
+    "msg": {
+      "type": "string"
+    },
+    "name": {
+      "type": "string"
+    },
+    "next": {
+      "properties": {
+        "tool": {
+          "type": "string"
+        },
+        "why": {
+          "type": "string"
+        }
+      },
+      "type": "object"
+    },
+    "next_unix": {
+      "type": "integer"
+    },
+    "ok": {
+      "type": "boolean"
+    },
+    "onboarding": {
+      "properties": {
+        "claim_url": {
+          "type": "string"
+        },
+        "invited_by": {
+          "type": "string"
+        },
+        "shared_tools": {
+          "items": {
+            "type": "string"
+          },
+          "type": "array"
+        },
+        "tenant": {
+          "type": "string"
+        },
+        "url": {
+          "type": "string"
+        }
+      },
+      "type": "object"
+    },
+    "payload": {
+      "properties": {
+        "ok": {
+          "type": "boolean"
+        },
+        "pong": {
+          "type": "boolean"
+        }
+      },
+      "type": "object"
+    },
+    "preset": {
+      "type": "null"
+    },
+    "result": {
+      "properties": {
+        "region": {
+          "type": "string"
+        },
+        "rows": {
+          "type": "string"
+        }
+      },
+      "type": "object"
+    },
+    "rows": {
+      "items": {
+        "properties": {
+          "body": {
+            "properties": {
+              "id": {
+                "type": "string"
+              }
+            },
+            "type": "object"
+          },
+          "checked_at": {
+            "type": "integer"
+          },
+          "delivery_id": {
+            "type": "null"
+          },
+          "id": {
+            "type": "string"
+          },
+          "latency_ms": {
+            "type": "integer"
+          },
+          "ok": {
+            "type": "boolean"
+          },
+          "received_at": {
+            "type": "integer"
+          },
+          "status": {
+            "type": "string"
+          },
+          "url": {
+            "type": "string"
+          }
+        },
+        "type": "object"
+      },
+      "type": "array"
+    },
+    "run_id": {
+      "type": "string"
+    },
+    "schedule": {
+      "type": "string"
+    },
+    "status": {
+      "type": [
+        "string",
+        "integer"
+      ]
+    },
+    "steps": {
+      "items": {
+        "properties": {
+          "result": {
+            "properties": {
+              "region": {
+                "type": "string"
+              },
+              "rows": {
+                "type": "string"
+              },
+              "url": {
+                "type": "string"
+              }
+            },
+            "type": "object"
+          },
+          "status": {
+            "type": "string"
+          },
+          "step": {
+            "type": "integer"
+          },
+          "tool": {
+            "type": "string"
+          }
+        },
+        "type": "object"
+      },
+      "type": "array"
+    },
+    "text": {
+      "type": "string"
+    },
+    "tool": {
+      "type": "string"
+    },
+    "tz": {
+      "type": "null"
+    },
+    "unverified": {
+      "type": "boolean"
+    },
+    "url": {
+      "type": "string"
+    },
+    "v1": {
+      "type": "string"
+    },
+    "verify": {
+      "properties": {
+        "allow_unverified": {
+          "type": "boolean"
+        },
+        "scheme": {
+          "type": "string"
+        }
+      },
+      "type": "object"
+    },
+    "welcome_back": {
+      "properties": {
+        "last_note": {
+          "type": "null"
+        },
+        "last_seen": {
+          "type": "string"
+        },
+        "notes": {
+          "type": "integer"
+        },
+        "since_you_left": {
+          "properties": {
+            "calls": {
+              "type": "integer"
+            },
+            "days": {
+              "type": "integer"
+            },
+            "inbox": {
+              "type": "integer"
+            },
+            "runs": {
+              "type": "integer"
+            }
+          },
+          "type": "object"
+        }
+      },
+      "type": "object"
+    }
+  },
+  "type": "object"
+}

Changed1 schema field changedOct 12, 2026

addedInput schema / properties / dry_run

Added value: +{
+  "description": "Ask instead of call: runs every admission check the real call runs, dispatches nothing, writes no call row, and returns {fits, units, remaining, refusal}; same as host.estimate. Default false.",
+  "type": "boolean"
+}

Changed1 schema field changedOct 9, 2026

addedInput schema / properties / budget / properties

Added value: +{
+  "max_child_calls": {
+    "description": "Free-plan ceiling 20; pro ceiling 50. Maximum shown is the free floor -- see host.quickstart limits.plan.budget for your plan.",
+    "maximum": 20,
+    "minimum": 1,
+    "type": "integer"
+  },
+  "max_est_tokens": {
+    "description": "Free-plan ceiling 200000; pro ceiling 2000000. Maximum shown is the free floor -- see host.quickstart limits.plan.budget for your plan.",
+    "maximum": 200000,
+    "minimum": 1,
+    "type": "integer"
+  },
+  "max_tool_latency_ms": {
+    "description": "Free-plan ceiling 30000; pro ceiling 120000. Maximum shown is the free floor -- see host.quickstart limits.plan.budget for your plan.",
+    "maximum": 30000,
+    "minimum": 1,
+    "type": "integer"
+  },
+  "max_wall_ms": {
+    "description": "Free-plan ceiling 60000; pro ceiling 600000. Maximum shown is the free floor -- see host.quickstart limits.plan.budget for your plan.",
+    "maximum": 60000,
+    "minimum": 1,
+    "type": "integer"
+  }
+}

Changed1 schema field changedOct 5, 2026

addedInput schema / properties / budget

Added value: +{
+  "description": "Lowers this call's budget below the plan default: any subset of max_child_calls, max_est_tokens, max_tool_latency_ms, max_wall_ms. A value above the plan's own ceiling is a validation error naming it; see host.runs.get's progress.budget.",
+  "type": "object"
+}

Changed1 schema field changedOct 4, 2026

changedInput schema / properties / tenant_key / description

Previous value: -"The key `signup` returned. Optional on the connection that ran signup (or host.redeem): that connection is already bound to the tenant it created, so later calls on it need no tenant_key. Required only when this connection carries no Authorization: Bearer header and never ran signup -- when both a header and this argument are present, the header wins. Omitting it on such a connection returns tenant_key_missing (-32602)."New value: +"The key `signup` returned. Optional on the connection that ran signup (or host.redeem): that connection is already bound to the tenant it created, so later calls on it need no tenant_key. On a connection with no Authorization: Bearer header and no prior signup, omitting it implicitly signs that connection up as a brand-new tenant and runs this call as it -- see host.whoami's source field. When both a header and this argument are present, the header wins."

Changed1 schema field changedOct 4, 2026

addedInput schema / x-deprecated

Added value: +{
+  "replaced_by": "host.tool.call",
+  "sunset": "2026-12-31"
+}

Changed1 schema field changedOct 3, 2026
- addedInput schema / additionalProperties
```
Added value: +false
```

Changed1 schema field changedSep 30, 2026

changedInput schema / properties / tenant_key / description

Previous value: -"The key `signup` returned. Required only when this connection carries no Authorization: Bearer header -- when both are present, the header wins. Omitting it on a connection with no header returns tenant_key_missing (-32602)."New value: +"The key `signup` returned. Optional on the connection that ran signup (or host.redeem): that connection is already bound to the tenant it created, so later calls on it need no tenant_key. Required only when this connection carries no Authorization: Bearer header and never ran signup -- when both a header and this argument are present, the header wins. Omitting it on such a connection returns tenant_key_missing (-32602)."

Changed1 schema field changedSep 30, 2026

changedInput schema / properties / tenant_key / description

Previous value: -"The key `signup` returned. Required only when this connection carries no Authorization: Bearer header -- when both are present, the header wins."New value: +"The key `signup` returned. Required only when this connection carries no Authorization: Bearer header -- when both are present, the header wins. Omitting it on a connection with no header returns tenant_key_missing (-32602)."

Changed1 schema field changedSep 23, 2026

addedInput schema / properties / version

Added value: +{
+  "description": "Pin the call to this version instead of whichever is current; see host.tool_history. An unknown version is an argument error.",
+  "type": "integer"
+}

Changed3 schema fields changedSep 11, 2026

addedInput schema / properties / args / description

Added value: +"Arguments to pass, validated against the tool's own args_schema."

addedInput schema / properties / async

Added value: +{
+  "description": "Run as a job instead of inline: returns {run_id, status} within ~50ms under the plan's job_max_s deadline; default false.",
+  "type": "boolean"
+}

addedInput schema / properties / name / description

Added value: +"Local name of the tool to invoke."

First observedSep 6, 2026

TDQS

Score is being calculated.

All mcphost tools Inspect

Try in Browser

Shareable, User-Owned Context BackendPeople, applications, and agents read, write, and coordinate together in one context lake. Reach it over MCP, a CLI, a Python SDK, or REST.fulcradynamics.comAd

Glama MCP Gateway

Add one secure layer between your agents and this server.

host.tool_call

Input Schema

Output Schema

Schema Changelog

TDQS

Glama MCP Gateway

Resources