Nansen

by io.github.hurcanNansen

Overview Discussions Admin

Loading prediction market prices

prediction_market_ohlcv

Read-only

Historical odds/volume candles for a Polymarket market.

When to use:

Current odds / implied probability, price history, and recent probability changes on a specific market.

Key fields:

Close is the share price for the displayed outcome side.
In binary markets, Yes and No shares are complementary and sum to about $1.

Pitfalls:

Each response is for one exact marketId — do not mix dates or prices across different markets.
If no candles are returned for the requested window, say so directly — do not estimate.

Prerequisites: If marketId is unknown, call prediction_market_lookup first.

Input Schema

Name	Required	Description	Default
`request`	Yes	Request for historical prediction market OHLCV.

Output Schema

Name	Required	Description	Default
`result`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

Changed6 schema fields changedOct 28, 2026

addedInput schema / properties / request / additionalProperties
```
Added value: +false
```

removedInput schema / properties / request / anyOf

Removed value: -[
-  {
-    "additionalProperties": true,
-    "type": "object"
-  },
-  {
-    "additionalProperties": false,
-    "description": "Request for historical prediction market OHLCV.",
-    "properties": {
-      "dateRange": {
-        "anyOf": [
-          {
-            "description": "Date range via tokens or dates.\nTokens: NOW, ALL_TIME, XMIN_AGO, XD_AGO, XH_AGO, XY_AGO; THIS_YEAR_START, THIS_QUARTER_START, THIS_MONTH_START, THIS_WEEK_START, TODAY_START; LAST_WEEK_START/END, LAST_MONTH_START/END, LAST_QUARTER_START/END, LAST_YEAR_START/END.\nDurations are exact rolling UTC timestamps at both ends: 1D_AGO equals 24H_AGO; 1Y_AGO equals 365 days. Bare duration aliases and case variants are supported.\nExplicit dates and calendar tokens keep calendar boundaries and inclusive final dates. TODAY_START is current-day midnight. Date-only endpoints keep their calendar contracts.\nALL_TIME is full history. It resolves to 2009-01-03. Use ALL_TIME instead of a very large day count.\nWeek starts Monday. Quarters are calendar. Dates: YYYY-MM-DD or ___-MM-DD (year omitted).\nPlease check detailed system instructions for more information.",
-            "properties": {
-              "from": {
-                "description": "Start token or date (YYYY-MM-DD or ___-MM-DD). Durations use exact rolling UTC timestamps; dates and calendar tokens start at midnight.",
-                "type": "string"
-              },
-              "to": {
-                "description": "End token or date (YYYY-MM-DD or ___-MM-DD). Durations use exact rolling UTC timestamps without an extra day. Dates and calendar tokens include the final date; TODAY_START stays at midnight.",
-                "type": "string"
-              }
-            },
-            "required": [
-              "from",
-              "to"
-            ],
-            "type": "object"
-          },
-          {
-            "type": "null"
-          }
-        ],
-        "default": null,
-        "description": "Optional date range for OHLCV. Defaults to the last 30 days when omitted."
-      },
-      "marketId": {
-        "description": "Numeric Polymarket market ID (e.g. '654412'). Obtain this from the prediction_market_screener tool.",
-        "maxLength": 100,
-        "minLength": 1,
-        "type": "string"
-      },
-      "orderBy": {
-        "anyOf": [
-          {
-            "enum": [
-              "period_start",
-              "volume_usd",
-              "trade_count"
-            ],
-            "type": "string"
-          },
-          {
-            "type": "null"
-          }
-        ],
-        "default": null,
-        "description": "Sort field. Pass an exact value above or None for default ('period_start')."
-      },
-      "orderByDirection": {
-        "default": "DESC",
-        "description": "Sort direction: 'ASC' or 'DESC' (case-insensitive).",
-        "enum": [
-          "ASC",
-          "DESC",
-          "asc",
-          "desc"
-        ],
-        "type": "string"
-      },
-      "page": {
-        "default": 1,
-        "description": "Page number for paginated results.",
-        "minimum": 1,
-        "type": "integer"
-      }
-    },
-    "required": [
-      "marketId"
-    ],
-    "type": "object"
-  }
-]

addedInput schema / properties / request / description

Added value: +"Request for historical prediction market OHLCV."

addedInput schema / properties / request / properties

Added value: +{
+  "dateRange": {
+    "anyOf": [
+      {
+        "additionalProperties": false,
+        "description": "Date range via tokens or dates.\nTokens: NOW, ALL_TIME, XMIN_AGO, XD_AGO, XH_AGO, XY_AGO; THIS_YEAR_START, THIS_QUARTER_START, THIS_MONTH_START, THIS_WEEK_START, TODAY_START; LAST_WEEK_START/END, LAST_MONTH_START/END, LAST_QUARTER_START/END, LAST_YEAR_START/END.\nDurations are exact rolling UTC timestamps at both ends: 1D_AGO equals 24H_AGO; 1Y_AGO equals 365 days. Bare duration aliases and case variants are supported.\nExplicit dates and calendar tokens keep calendar boundaries and inclusive final dates. TODAY_START is current-day midnight. Date-only endpoints keep their calendar contracts.\nALL_TIME is full history. It resolves to 2009-01-03. Use ALL_TIME instead of a very large day count.\nWeek starts Monday. Quarters are calendar. Dates: YYYY-MM-DD or ___-MM-DD (year omitted).\nPlease check detailed system instructions for more information.",
+        "properties": {
+          "from": {
+            "description": "Start token or date (YYYY-MM-DD or ___-MM-DD). Durations use exact rolling UTC timestamps; dates and calendar tokens start at midnight.",
+            "type": "string"
+          },
+          "to": {
+            "description": "End token or date (YYYY-MM-DD or ___-MM-DD). Durations use exact rolling UTC timestamps without an extra day. Dates and calendar tokens include the final date; TODAY_START stays at midnight.",
+            "type": "string"
+          }
+        },
+        "required": [
+          "from",
+          "to"
+        ],
+        "type": "object"
+      },
+      {
+        "type": "null"
+      }
+    ],
+    "default": null,
+    "description": "Optional date range for OHLCV. Defaults to the last 30 days when omitted."
+  },
+  "marketId": {
+    "description": "Numeric Polymarket market ID (e.g. '654412'). Obtain this from the prediction_market_screener tool.",
+    "maxLength": 100,
+    "minLength": 1,
+    "type": "string"
+  },
+  "orderBy": {
+    "anyOf": [
+      {
+        "enum": [
+          "period_start",
+          "volume_usd",
+          "trade_count"
+        ],
+        "type": "string"
+      },
+      {
+        "type": "null"
+      }
+    ],
+    "default": null,
+    "description": "Sort field. Pass an exact value above or None for default ('period_start')."
+  },
+  "orderByDirection": {
+    "default": "DESC",
+    "description": "Sort direction: 'ASC' or 'DESC' (case-insensitive).",
+    "enum": [
+      "ASC",
+      "DESC",
+      "asc",
+      "desc"
+    ],
+    "type": "string"
+  },
+  "page": {
+    "default": 1,
+    "description": "Page number for paginated results.",
+    "minimum": 1,
+    "type": "integer"
+  }
+}

addedInput schema / properties / request / required
```
Added value: +[
+  "marketId"
+]
```
addedInput schema / properties / request / type
```
Added value: +"object"
```

Changed1 schema field changedOct 10, 2026

changedInput schema / properties / request / anyOf

Previous value: -[
-  {
-    "additionalProperties": true,
-    "type": "object"
-  },
-  {
-    "additionalProperties": false,
-    "description": "Request for historical prediction market OHLCV.",
-    "properties": {
-      "dateRange": {
-        "anyOf": [
-          {
-            "description": "Date range via tokens or dates.\nTokens: NOW, ALL_TIME, XMIN_AGO, XD_AGO, XH_AGO; THIS_YEAR_START, THIS_QUARTER_START, THIS_MONTH_START, THIS_WEEK_START, TODAY_START; LAST_WEEK_START/END, LAST_MONTH_START/END, LAST_QUARTER_START/END, LAST_YEAR_START/END.\nALL_TIME is full history. It resolves to 2009-01-03. Use ALL_TIME instead of a very large day count.\nWeek starts Monday. Quarters are calendar. Dates: YYYY-MM-DD or ___-MM-DD (year omitted).\nPlease check detailed system instructions for more information.",
-            "properties": {
-              "from": {
-                "description": "Start value: token (see above) or date (YYYY-MM-DD or ___-MM-DD).",
-                "type": "string"
-              },
-              "to": {
-                "description": "End value: token (see above) or date (YYYY-MM-DD or ___-MM-DD).",
-                "type": "string"
-              }
-            },
-            "required": [
-              "from",
-              "to"
-            ],
-            "type": "object"
-          },
-          {
-            "type": "null"
-          }
-        ],
-        "default": null,
-        "description": "Optional date range for OHLCV. Defaults to the last 30 days when omitted."
-      },
-      "marketId": {
-        "description": "Numeric Polymarket market ID (e.g. '654412'). Obtain this from the prediction_market_screener tool.",
-        "maxLength": 100,
-        "minLength": 1,
-        "type": "string"
-      },
-      "orderBy": {
-        "anyOf": [
-          {
-            "enum": [
-              "period_start",
-              "volume_usd",
-              "trade_count"
-            ],
-            "type": "string"
-          },
-          {
-            "type": "null"
-          }
-        ],
-        "default": null,
-        "description": "Sort field. Pass an exact value above or None for default ('period_start')."
-      },
-      "orderByDirection": {
-        "default": "DESC",
-        "description": "Sort direction: 'ASC' or 'DESC' (case-insensitive).",
-        "enum": [
-          "ASC",
-          "DESC",
-          "asc",
-          "desc"
-        ],
-        "type": "string"
-      },
-      "page": {
-        "default": 1,
-        "description": "Page number for paginated results.",
-        "minimum": 1,
-        "type": "integer"
-      }
-    },
-    "required": [
-      "marketId"
-    ],
-    "type": "object"
-  }
-]New value: +[
+  {
+    "additionalProperties": true,
+    "type": "object"
+  },
+  {
+    "additionalProperties": false,
+    "description": "Request for historical prediction market OHLCV.",
+    "properties": {
+      "dateRange": {
+        "anyOf": [
+          {
+            "description": "Date range via tokens or dates.\nTokens: NOW, ALL_TIME, XMIN_AGO, XD_AGO, XH_AGO, XY_AGO; THIS_YEAR_START, THIS_QUARTER_START, THIS_MONTH_START, THIS_WEEK_START, TODAY_START; LAST_WEEK_START/END, LAST_MONTH_START/END, LAST_QUARTER_START/END, LAST_YEAR_START/END.\nDurations are exact rolling UTC timestamps at both ends: 1D_AGO equals 24H_AGO; 1Y_AGO equals 365 days. Bare duration aliases and case variants are supported.\nExplicit dates and calendar tokens keep calendar boundaries and inclusive final dates. TODAY_START is current-day midnight. Date-only endpoints keep their calendar contracts.\nALL_TIME is full history. It resolves to 2009-01-03. Use ALL_TIME instead of a very large day count.\nWeek starts Monday. Quarters are calendar. Dates: YYYY-MM-DD or ___-MM-DD (year omitted).\nPlease check detailed system instructions for more information.",
+            "properties": {
+              "from": {
+                "description": "Start token or date (YYYY-MM-DD or ___-MM-DD). Durations use exact rolling UTC timestamps; dates and calendar tokens start at midnight.",
+                "type": "string"
+              },
+              "to": {
+                "description": "End token or date (YYYY-MM-DD or ___-MM-DD). Durations use exact rolling UTC timestamps without an extra day. Dates and calendar tokens include the final date; TODAY_START stays at midnight.",
+                "type": "string"
+              }
+            },
+            "required": [
+              "from",
+              "to"
+            ],
+            "type": "object"
+          },
+          {
+            "type": "null"
+          }
+        ],
+        "default": null,
+        "description": "Optional date range for OHLCV. Defaults to the last 30 days when omitted."
+      },
+      "marketId": {
+        "description": "Numeric Polymarket market ID (e.g. '654412'). Obtain this from the prediction_market_screener tool.",
+        "maxLength": 100,
+        "minLength": 1,
+        "type": "string"
+      },
+      "orderBy": {
+        "anyOf": [
+          {
+            "enum": [
+              "period_start",
+              "volume_usd",
+              "trade_count"
+            ],
+            "type": "string"
+          },
+          {
+            "type": "null"
+          }
+        ],
+        "default": null,
+        "description": "Sort field. Pass an exact value above or None for default ('period_start')."
+      },
+      "orderByDirection": {
+        "default": "DESC",
+        "description": "Sort direction: 'ASC' or 'DESC' (case-insensitive).",
+        "enum": [
+          "ASC",
+          "DESC",
+          "asc",
+          "desc"
+        ],
+        "type": "string"
+      },
+      "page": {
+        "default": 1,
+        "description": "Page number for paginated results.",
+        "minimum": 1,
+        "type": "integer"
+      }
+    },
+    "required": [
+      "marketId"
+    ],
+    "type": "object"
+  }
+]

Changed1 schema field changedSep 29, 2026

changedInput schema / properties / request / anyOf

Previous value: -[
-  {
-    "additionalProperties": true,
-    "type": "object"
-  },
-  {
-    "additionalProperties": false,
-    "description": "Request for historical prediction market OHLCV.",
-    "properties": {
-      "dateRange": {
-        "anyOf": [
-          {
-            "description": "Date range via tokens or dates.\nTokens: NOW, XMIN_AGO, XD_AGO, XH_AGO; THIS_YEAR_START, THIS_QUARTER_START, THIS_MONTH_START, THIS_WEEK_START, TODAY_START; LAST_WEEK_START/END, LAST_MONTH_START/END, LAST_QUARTER_START/END, LAST_YEAR_START/END.\nWeek starts Monday. Quarters are calendar. Dates: YYYY-MM-DD or ___-MM-DD (year omitted).\nPlease check detailed system instructions for more information.",
-            "properties": {
-              "from": {
-                "description": "Start value: token (see above) or date (YYYY-MM-DD or ___-MM-DD).",
-                "type": "string"
-              },
-              "to": {
-                "description": "End value: token (see above) or date (YYYY-MM-DD or ___-MM-DD).",
-                "type": "string"
-              }
-            },
-            "required": [
-              "from",
-              "to"
-            ],
-            "type": "object"
-          },
-          {
-            "type": "null"
-          }
-        ],
-        "default": null,
-        "description": "Optional date range for OHLCV. Defaults to the last 30 days when omitted."
-      },
-      "marketId": {
-        "description": "Numeric Polymarket market ID (e.g. '654412'). Obtain this from the prediction_market_screener tool.",
-        "maxLength": 100,
-        "minLength": 1,
-        "type": "string"
-      },
-      "orderBy": {
-        "anyOf": [
-          {
-            "enum": [
-              "period_start",
-              "volume_usd",
-              "trade_count"
-            ],
-            "type": "string"
-          },
-          {
-            "type": "null"
-          }
-        ],
-        "default": null,
-        "description": "Sort field. Pass an exact value above or None for default ('period_start')."
-      },
-      "orderByDirection": {
-        "default": "DESC",
-        "description": "Sort direction: 'ASC' or 'DESC' (case-insensitive).",
-        "enum": [
-          "ASC",
-          "DESC",
-          "asc",
-          "desc"
-        ],
-        "type": "string"
-      },
-      "page": {
-        "default": 1,
-        "description": "Page number for paginated results.",
-        "minimum": 1,
-        "type": "integer"
-      }
-    },
-    "required": [
-      "marketId"
-    ],
-    "type": "object"
-  }
-]New value: +[
+  {
+    "additionalProperties": true,
+    "type": "object"
+  },
+  {
+    "additionalProperties": false,
+    "description": "Request for historical prediction market OHLCV.",
+    "properties": {
+      "dateRange": {
+        "anyOf": [
+          {
+            "description": "Date range via tokens or dates.\nTokens: NOW, ALL_TIME, XMIN_AGO, XD_AGO, XH_AGO; THIS_YEAR_START, THIS_QUARTER_START, THIS_MONTH_START, THIS_WEEK_START, TODAY_START; LAST_WEEK_START/END, LAST_MONTH_START/END, LAST_QUARTER_START/END, LAST_YEAR_START/END.\nALL_TIME is full history. It resolves to 2009-01-03. Use ALL_TIME instead of a very large day count.\nWeek starts Monday. Quarters are calendar. Dates: YYYY-MM-DD or ___-MM-DD (year omitted).\nPlease check detailed system instructions for more information.",
+            "properties": {
+              "from": {
+                "description": "Start value: token (see above) or date (YYYY-MM-DD or ___-MM-DD).",
+                "type": "string"
+              },
+              "to": {
+                "description": "End value: token (see above) or date (YYYY-MM-DD or ___-MM-DD).",
+                "type": "string"
+              }
+            },
+            "required": [
+              "from",
+              "to"
+            ],
+            "type": "object"
+          },
+          {
+            "type": "null"
+          }
+        ],
+        "default": null,
+        "description": "Optional date range for OHLCV. Defaults to the last 30 days when omitted."
+      },
+      "marketId": {
+        "description": "Numeric Polymarket market ID (e.g. '654412'). Obtain this from the prediction_market_screener tool.",
+        "maxLength": 100,
+        "minLength": 1,
+        "type": "string"
+      },
+      "orderBy": {
+        "anyOf": [
+          {
+            "enum": [
+              "period_start",
+              "volume_usd",
+              "trade_count"
+            ],
+            "type": "string"
+          },
+          {
+            "type": "null"
+          }
+        ],
+        "default": null,
+        "description": "Sort field. Pass an exact value above or None for default ('period_start')."
+      },
+      "orderByDirection": {
+        "default": "DESC",
+        "description": "Sort direction: 'ASC' or 'DESC' (case-insensitive).",
+        "enum": [
+          "ASC",
+          "DESC",
+          "asc",
+          "desc"
+        ],
+        "type": "string"
+      },
+      "page": {
+        "default": 1,
+        "description": "Page number for paginated results.",
+        "minimum": 1,
+        "type": "integer"
+      }
+    },
+    "required": [
+      "marketId"
+    ],
+    "type": "object"
+  }
+]

Changed1 schema field changedMay 29, 2026

changedInput schema / properties / request / anyOf

Previous value: -[
-  {
-    "additionalProperties": true,
-    "type": "object"
-  },
-  {
-    "additionalProperties": false,
-    "description": "Request for historical prediction market OHLCV.",
-    "properties": {
-      "dateRange": {
-        "anyOf": [
-          {
-            "description": "Date range via tokens or dates.\nTokens: NOW, XMIN_AGO, XD_AGO, XH_AGO; THIS_YEAR_START, THIS_QUARTER_START, THIS_MONTH_START, THIS_WEEK_START, TODAY_START; LAST_WEEK_START/END, LAST_MONTH_START/END, LAST_QUARTER_START/END, LAST_YEAR_START/END.\nWeek starts Monday. Quarters are calendar. Dates: YYYY-MM-DD or ___-MM-DD (year omitted).\nPlease check detailed system instructions for more information.",
-            "properties": {
-              "from": {
-                "description": "Start value: token (see above) or date (YYYY-MM-DD or ___-MM-DD).",
-                "type": "string"
-              },
-              "to": {
-                "description": "End value: token (see above) or date (YYYY-MM-DD or ___-MM-DD).",
-                "type": "string"
-              }
-            },
-            "required": [
-              "from",
-              "to"
-            ],
-            "type": "object"
-          },
-          {
-            "type": "null"
-          }
-        ],
-        "default": null,
-        "description": "Optional date range for OHLCV. Defaults to the last 30 days when omitted."
-      },
-      "marketId": {
-        "description": "Numeric Polymarket market ID (e.g. '654412'). Obtain this from the prediction_market_screener tool.",
-        "maxLength": 100,
-        "minLength": 1,
-        "type": "string"
-      },
-      "orderBy": {
-        "anyOf": [
-          {
-            "type": "string"
-          },
-          {
-            "type": "null"
-          }
-        ],
-        "default": null,
-        "description": "Optional sort field. Common fields: periodStart, volumeUsd, tradeCount."
-      },
-      "orderByDirection": {
-        "default": "desc",
-        "description": "Sort direction when orderBy is provided.",
-        "enum": [
-          "asc",
-          "desc",
-          "ASC",
-          "DESC"
-        ],
-        "type": "string"
-      },
-      "page": {
-        "default": 1,
-        "description": "Page number for paginated results.",
-        "minimum": 1,
-        "type": "integer"
-      }
-    },
-    "required": [
-      "marketId"
-    ],
-    "type": "object"
-  }
-]New value: +[
+  {
+    "additionalProperties": true,
+    "type": "object"
+  },
+  {
+    "additionalProperties": false,
+    "description": "Request for historical prediction market OHLCV.",
+    "properties": {
+      "dateRange": {
+        "anyOf": [
+          {
+            "description": "Date range via tokens or dates.\nTokens: NOW, XMIN_AGO, XD_AGO, XH_AGO; THIS_YEAR_START, THIS_QUARTER_START, THIS_MONTH_START, THIS_WEEK_START, TODAY_START; LAST_WEEK_START/END, LAST_MONTH_START/END, LAST_QUARTER_START/END, LAST_YEAR_START/END.\nWeek starts Monday. Quarters are calendar. Dates: YYYY-MM-DD or ___-MM-DD (year omitted).\nPlease check detailed system instructions for more information.",
+            "properties": {
+              "from": {
+                "description": "Start value: token (see above) or date (YYYY-MM-DD or ___-MM-DD).",
+                "type": "string"
+              },
+              "to": {
+                "description": "End value: token (see above) or date (YYYY-MM-DD or ___-MM-DD).",
+                "type": "string"
+              }
+            },
+            "required": [
+              "from",
+              "to"
+            ],
+            "type": "object"
+          },
+          {
+            "type": "null"
+          }
+        ],
+        "default": null,
+        "description": "Optional date range for OHLCV. Defaults to the last 30 days when omitted."
+      },
+      "marketId": {
+        "description": "Numeric Polymarket market ID (e.g. '654412'). Obtain this from the prediction_market_screener tool.",
+        "maxLength": 100,
+        "minLength": 1,
+        "type": "string"
+      },
+      "orderBy": {
+        "anyOf": [
+          {
+            "enum": [
+              "period_start",
+              "volume_usd",
+              "trade_count"
+            ],
+            "type": "string"
+          },
+          {
+            "type": "null"
+          }
+        ],
+        "default": null,
+        "description": "Sort field. Pass an exact value above or None for default ('period_start')."
+      },
+      "orderByDirection": {
+        "default": "DESC",
+        "description": "Sort direction: 'ASC' or 'DESC' (case-insensitive).",
+        "enum": [
+          "ASC",
+          "DESC",
+          "asc",
+          "desc"
+        ],
+        "type": "string"
+      },
+      "page": {
+        "default": 1,
+        "description": "Page number for paginated results.",
+        "minimum": 1,
+        "type": "integer"
+      }
+    },
+    "required": [
+      "marketId"
+    ],
+    "type": "object"
+  }
+]

Changed3 schema fields changedMay 19, 2026

removedInput schema / $defs

Removed value: -{
-  "DateRange": {
-    "description": "Date range via tokens or dates.\nTokens: NOW, XMIN_AGO, XD_AGO, XH_AGO; THIS_YEAR_START, THIS_QUARTER_START, THIS_MONTH_START, THIS_WEEK_START, TODAY_START; LAST_WEEK_START/END, LAST_MONTH_START/END, LAST_QUARTER_START/END, LAST_YEAR_START/END.\nWeek starts Monday. Quarters are calendar. Dates: YYYY-MM-DD or ___-MM-DD (year omitted).\nPlease check detailed system instructions for more information.",
-    "properties": {
-      "from": {
-        "description": "Start value: token (see above) or date (YYYY-MM-DD or ___-MM-DD).",
-        "type": "string"
-      },
-      "to": {
-        "description": "End value: token (see above) or date (YYYY-MM-DD or ___-MM-DD).",
-        "type": "string"
-      }
-    },
-    "required": [
-      "from",
-      "to"
-    ],
-    "type": "object"
-  },
-  "PredictionMarketOhlcvRequest": {
-    "description": "Request for historical prediction market OHLCV.",
-    "properties": {
-      "dateRange": {
-        "anyOf": [
-          {
-            "$ref": "#/$defs/DateRange"
-          },
-          {
-            "type": "null"
-          }
-        ],
-        "default": null,
-        "description": "Optional date range for OHLCV. Defaults to the last 30 days when omitted."
-      },
-      "marketId": {
-        "description": "Numeric Polymarket market ID (e.g. '654412'). Obtain this from the prediction_market_screener tool.",
-        "maxLength": 100,
-        "minLength": 1,
-        "type": "string"
-      },
-      "orderBy": {
-        "anyOf": [
-          {
-            "type": "string"
-          },
-          {
-            "type": "null"
-          }
-        ],
-        "default": null,
-        "description": "Optional sort field. Common fields: periodStart, volumeUsd, tradeCount."
-      },
-      "orderByDirection": {
-        "default": "desc",
-        "description": "Sort direction when orderBy is provided.",
-        "enum": [
-          "asc",
-          "desc",
-          "ASC",
-          "DESC"
-        ],
-        "type": "string"
-      },
-      "page": {
-        "default": 1,
-        "description": "Page number for paginated results.",
-        "minimum": 1,
-        "type": "integer"
-      }
-    },
-    "required": [
-      "marketId"
-    ],
-    "type": "object"
-  }
-}

addedInput schema / additionalProperties
```
Added value: +false
```

changedInput schema / properties / request / anyOf

Previous value: -[
-  {
-    "additionalProperties": true,
-    "type": "object"
-  },
-  {
-    "$ref": "#/$defs/PredictionMarketOhlcvRequest"
-  }
-]New value: +[
+  {
+    "additionalProperties": true,
+    "type": "object"
+  },
+  {
+    "additionalProperties": false,
+    "description": "Request for historical prediction market OHLCV.",
+    "properties": {
+      "dateRange": {
+        "anyOf": [
+          {
+            "description": "Date range via tokens or dates.\nTokens: NOW, XMIN_AGO, XD_AGO, XH_AGO; THIS_YEAR_START, THIS_QUARTER_START, THIS_MONTH_START, THIS_WEEK_START, TODAY_START; LAST_WEEK_START/END, LAST_MONTH_START/END, LAST_QUARTER_START/END, LAST_YEAR_START/END.\nWeek starts Monday. Quarters are calendar. Dates: YYYY-MM-DD or ___-MM-DD (year omitted).\nPlease check detailed system instructions for more information.",
+            "properties": {
+              "from": {
+                "description": "Start value: token (see above) or date (YYYY-MM-DD or ___-MM-DD).",
+                "type": "string"
+              },
+              "to": {
+                "description": "End value: token (see above) or date (YYYY-MM-DD or ___-MM-DD).",
+                "type": "string"
+              }
+            },
+            "required": [
+              "from",
+              "to"
+            ],
+            "type": "object"
+          },
+          {
+            "type": "null"
+          }
+        ],
+        "default": null,
+        "description": "Optional date range for OHLCV. Defaults to the last 30 days when omitted."
+      },
+      "marketId": {
+        "description": "Numeric Polymarket market ID (e.g. '654412'). Obtain this from the prediction_market_screener tool.",
+        "maxLength": 100,
+        "minLength": 1,
+        "type": "string"
+      },
+      "orderBy": {
+        "anyOf": [
+          {
+            "type": "string"
+          },
+          {
+            "type": "null"
+          }
+        ],
+        "default": null,
+        "description": "Optional sort field. Common fields: periodStart, volumeUsd, tradeCount."
+      },
+      "orderByDirection": {
+        "default": "desc",
+        "description": "Sort direction when orderBy is provided.",
+        "enum": [
+          "asc",
+          "desc",
+          "ASC",
+          "DESC"
+        ],
+        "type": "string"
+      },
+      "page": {
+        "default": 1,
+        "description": "Page number for paginated results.",
+        "minimum": 1,
+        "type": "integer"
+      }
+    },
+    "required": [
+      "marketId"
+    ],
+    "type": "object"
+  }
+]

AddedMar 25, 2026

TDQS

A3.9/5.0

Behavior4/5

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

Annotations already declare readOnly, openWorld, and non-destructive, so the safety profile is covered. The description adds real behavioral context beyond that: it warns not to mix dates/prices across markets, and instructs the agent to say so directly rather than estimate when no candles are returned. These are useful operating constraints not captured by annotations.

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

Conciseness4/5

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

The description is front-loaded with purpose followed by clearly labeled sections (When to use, Key fields, Pitfalls, Prerequisites). Every section adds value, though the bold-headed formatting is slightly heavier than strictly necessary for a single-parameter tool.

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

Completeness4/5

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

An output schema exists, so the description needn't explain return values, and it still adds the important note about Close signifying the displayed outcome side. It covers the prerequisites and pitfalls an agent needs. The only minor gap is not distinguishing itself from orderbook/trades siblings for overlapping use cases.

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

Parameters3/5

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

Schema coverage is 100%, and the description adds no direct guidance on parameters like dateRange or orderBy beyond saying it defaults to the last 30 days (also in schema). The Close/Yes-No complementarity note explains output semantics rather than parameters. Baseline 3 is appropriate when the schema does the heavy lifting.

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

Purpose4/5

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

The description opens with a specific verb+resource: 'Historical odds/volume candles for a Polymarket market.' This clearly distinguishes it from siblings like prediction_market_orderbook and prediction_market_trades. It doesn't contrast with sibling alternatives explicitly, so it falls short of a 5, but the purpose is unambiguous.

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

Usage Guidelines4/5

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

A dedicated 'When to use' section names price history and recent probability changes, and the Prerequisites section routes to prediction_market_lookup when marketId is unknown. It lacks explicit 'when not to use' guidance (e.g., use orderbook for current depth or trades for individual fills), so it lands at 4 rather than 5.

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

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