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Clear a single metric

clear_metric

DestructiveIdempotent

Clear a single day's metric value (e.g., steps, mood) to null, undoing incorrect entries without affecting other metrics. Resets that metric to 'nothing recorded' for that day.

Instructions

Blank out (set to null) a single metric for a single day, without touching that day's other metrics. The counterpart to log_daily_metric for undoing a bad value — e.g. a mood logged for the wrong day, or a weight entered with the wrong units. Clears everything recorded for that metric/day — including individual log_measurement readings or imported rows, not just a value log_daily_metric wrote directly — so the metric genuinely goes back to "nothing recorded" rather than falling back to a blended value from whatever else is left.

Privacy note: this server and its SQLite file are entirely local, but the data returned by this tool becomes part of the conversation sent to whatever model the calling client is configured with. If that model runs in the cloud rather than on your machine, treat this the same as pasting the data into a chat with that provider.

Input Schema

TableJSON Schema

Name	Required	Description	Default
`date`	Yes	The day to clear a field for, formatted YYYY-MM-DD.
`field`	Yes	Which metric to blank out. One of: steps, sleep_hours, resting_heart_rate, weight_kg, workout_minutes, mood, water_ml, heart_rate, hrv_ms.

Output Schema

TableJSON Schema

Name	Required	Description	Default
`row`	No
`note`	No
`cleared`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

Addedv1.0.16Sep 15, 2026
Removedv1.0.15Sep 15, 2026

Changed2 schema fields changedv1.0.11Sep 13, 2026

changedInput schema / properties / field / description

Previous value: -"Which metric to blank out. One of: steps, sleep_hours,\nresting_heart_rate, weight_kg, workout_minutes, mood, water_ml."New value: +"Which metric to blank out. One of: steps, sleep_hours,\nresting_heart_rate, weight_kg, workout_minutes, mood, water_ml, heart_rate, hrv_ms."

changedOutput schema / properties / row / anyOf

Previous value: -[
-  {
-    "properties": {
-      "date": {
-        "type": "string"
-      },
-      "mood": {
-        "anyOf": [
-          {
-            "type": "integer"
-          },
-          {
-            "type": "null"
-          }
-        ],
-        "default": null
-      },
-      "resting_heart_rate": {
-        "anyOf": [
-          {
-            "type": "integer"
-          },
-          {
-            "type": "null"
-          }
-        ],
-        "default": null
-      },
-      "sleep_hours": {
-        "anyOf": [
-          {
-            "type": "number"
-          },
-          {
-            "type": "null"
-          }
-        ],
-        "default": null
-      },
-      "steps": {
-        "anyOf": [
-          {
-            "type": "integer"
-          },
-          {
-            "type": "null"
-          }
-        ],
-        "default": null
-      },
-      "water_ml": {
-        "anyOf": [
-          {
-            "type": "integer"
-          },
-          {
-            "type": "null"
-          }
-        ],
-        "default": null
-      },
-      "weight_kg": {
-        "anyOf": [
-          {
-            "type": "number"
-          },
-          {
-            "type": "null"
-          }
-        ],
-        "default": null
-      },
-      "workout_minutes": {
-        "anyOf": [
-          {
-            "type": "integer"
-          },
-          {
-            "type": "null"
-          }
-        ],
-        "default": null
-      }
-    },
-    "required": [
-      "date"
-    ],
-    "type": "object"
-  },
-  {
-    "type": "null"
-  }
-]New value: +[
+  {
+    "properties": {
+      "date": {
+        "type": "string"
+      },
+      "heart_rate": {
+        "anyOf": [
+          {
+            "type": "integer"
+          },
+          {
+            "type": "null"
+          }
+        ],
+        "default": null
+      },
+      "hrv_ms": {
+        "anyOf": [
+          {
+            "type": "number"
+          },
+          {
+            "type": "null"
+          }
+        ],
+        "default": null
+      },
+      "mood": {
+        "anyOf": [
+          {
+            "type": "integer"
+          },
+          {
+            "type": "null"
+          }
+        ],
+        "default": null
+      },
+      "resting_heart_rate": {
+        "anyOf": [
+          {
+            "type": "integer"
+          },
+          {
+            "type": "null"
+          }
+        ],
+        "default": null
+      },
+      "sleep_hours": {
+        "anyOf": [
+          {
+            "type": "number"
+          },
+          {
+            "type": "null"
+          }
+        ],
+        "default": null
+      },
+      "steps": {
+        "anyOf": [
+          {
+            "type": "integer"
+          },
+          {
+            "type": "null"
+          }
+        ],
+        "default": null
+      },
+      "water_ml": {
+        "anyOf": [
+          {
+            "type": "integer"
+          },
+          {
+            "type": "null"
+          }
+        ],
+        "default": null
+      },
+      "weight_kg": {
+        "anyOf": [
+          {
+            "type": "number"
+          },
+          {
+            "type": "null"
+          }
+        ],
+        "default": null
+      },
+      "workout_minutes": {
+        "anyOf": [
+          {
+            "type": "integer"
+          },
+          {
+            "type": "null"
+          }
+        ],
+        "default": null
+      }
+    },
+    "required": [
+      "date"
+    ],
+    "type": "object"
+  },
+  {
+    "type": "null"
+  }
+]

Changed6 schema fields changedv1.0.8Sep 7, 2026

addedOutput schema / properties / cleared
```
Added value: +{
+  "type": "string"
+}
```

addedOutput schema / properties / note

Added value: +{
+  "anyOf": [
+    {
+      "type": "string"
+    },
+    {
+      "type": "null"
+    }
+  ],
+  "default": null
+}

removedOutput schema / properties / result

Removed value: -{
-  "type": "string"
-}

addedOutput schema / properties / row

Added value: +{
+  "anyOf": [
+    {
+      "properties": {
+        "date": {
+          "type": "string"
+        },
+        "mood": {
+          "anyOf": [
+            {
+              "type": "integer"
+            },
+            {
+              "type": "null"
+            }
+          ],
+          "default": null
+        },
+        "resting_heart_rate": {
+          "anyOf": [
+            {
+              "type": "integer"
+            },
+            {
+              "type": "null"
+            }
+          ],
+          "default": null
+        },
+        "sleep_hours": {
+          "anyOf": [
+            {
+              "type": "number"
+            },
+            {
+              "type": "null"
+            }
+          ],
+          "default": null
+        },
+        "steps": {
+          "anyOf": [
+            {
+              "type": "integer"
+            },
+            {
+              "type": "null"
+            }
+          ],
+          "default": null
+        },
+        "water_ml": {
+          "anyOf": [
+            {
+              "type": "integer"
+            },
+            {
+              "type": "null"
+            }
+          ],
+          "default": null
+        },
+        "weight_kg": {
+          "anyOf": [
+            {
+              "type": "number"
+            },
+            {
+              "type": "null"
+            }
+          ],
+          "default": null
+        },
+        "workout_minutes": {
+          "anyOf": [
+            {
+              "type": "integer"
+            },
+            {
+              "type": "null"
+            }
+          ],
+          "default": null
+        }
+      },
+      "required": [
+        "date"
+      ],
+      "type": "object"
+    },
+    {
+      "type": "null"
+    }
+  ],
+  "default": null
+}

changedOutput schema / required

Previous value: -[
-  "result"
-]New value: +[
+  "cleared"
+]

removedOutput schema / x-fastmcp-wrap-result
```
Removed value: -true
```

Addedv1.0.4Sep 2, 2026

TDQS

A4.4/5.0

Behavior5/5

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

The description goes well beyond the annotations' destructiveHint by detailing the full scope of destruction: it clears everything recorded for that metric/day, including individual log_measurement readings and imported rows, not just values written by log_daily_metric. It also adds a privacy note about data becoming part of the conversation sent to a model, which annotations do not cover.

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 main behavioral statement is front-loaded and precise, and the extra detail about clearing all related rows is necessary for a destructive tool. The privacy note adds relevant context but is somewhat tangential to invocation, keeping this from a perfect score.

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

Completeness5/5

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

For a two-parameter destructive operation, the description fully covers what the tool does, the scope of the destruction, and a privacy consideration. The output schema exists, so return-value details are not the description's responsibility.

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 description coverage is 100%, so the input schema already fully documents both parameters. The description reinforces the behavior ('set to null', 'single metric', 'single day') but does not add meaning beyond the schema, so the baseline of 3 is appropriate.

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

Purpose5/5

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

The description uses a precise verb ('blank out / set to null') and identifies the exact resource ('a single metric for a single day'), making the operation unmistakable. It also distinguishes itself from the sibling log_daily_metric by explicitly naming it as the counterpart for undoing a bad value.

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?

The description clearly explains when to use this tool: for undoing a bad value, with concrete examples like a mood logged for the wrong day or weight entered with wrong units. It does not enumerate explicit when-not-to-use cases or alternative tools, but the context is clear enough for an agent to route correctly.

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