signalint

Overview Schema Source Related Servers Discussions Admin

check_files

Read-onlyIdempotent

Run Oxlint, TypeScript, and optional Biome lint/type diagnostics on selected files; cached unchanged files are skipped for incremental post-edit checks.

Instructions

Runs Oxlint and TypeScript (and optionally Biome) lint and type diagnostics on a specific list of files, using per-engine content-hash caching to skip unchanged files. Read-only; no files are written or modified. Use this for incremental checks after editing specific files; use check_project for a full project scan. The files parameter expects relative file paths (not glob patterns) within the project directory — absolute paths or paths outside the root return an error response. Caching is file-content-hash-based: a file is re-checked only when its content or the engine's config file (e.g., .oxlintrc, tsconfig.json) has changed since the last call, not based on git status. TypeScript is a whole-program engine: it re-runs whenever any TypeScript file in the request has changed content.

Input Schema

TableJSON Schema

Name	Required	Description	Default
`files`	Yes

Output Schema

TableJSON Schema

Name	Required	Description	Default
`code`	No
`engine`	No
`status`	Yes
`checkId`	No
`engines`	No
`message`	No
`clusters`	No
`truncated`	No
`loopWarning`	No
`projectRoot`	No
`totalIssues`	No
`schemaVersion`	No
`fileRuleChurnWarning`	No

Schema Changelog

Changes observed during successful MCP inspections.

Changed7 schema fields changedv1.0.0Oct 6, 2026

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

changedOutput schema / properties / engine / enum

Previous value: -[
-  "oxlint",
-  "tsc",
-  "biome"
-]New value: +[
+  "oxlint",
+  "tsc",
+  "biome",
+  "eslint"
+]

addedOutput schema / properties / engines / properties / eslint

Added value: +{
+  "additionalProperties": false,
+  "properties": {
+    "message": {
+      "type": "string"
+    },
+    "status": {
+      "enum": [
+        "ok",
+        "error",
+        "disabled"
+      ],
+      "type": "string"
+    }
+  },
+  "required": [
+    "status"
+  ],
+  "type": "object"
+}

changedOutput schema / properties / engines / required

Previous value: -[
-  "oxlint",
-  "tsc",
-  "biome"
-]New value: +[
+  "oxlint",
+  "tsc",
+  "biome",
+  "eslint"
+]

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

changedOutput schema / properties / schemaVersion / enum

Previous value: -[
-  "1.2"
-]New value: +[
+  "1.3"
+]

changedOutput schema / properties / status / enum

Previous value: -[
-  "clean",
-  "issues_found",
-  "timeout",
-  "error"
-]New value: +[
+  "clean",
+  "issues_found",
+  "error"
+]

Changed2 schema fields changedv0.4.0Aug 21, 2026

addedOutput schema / properties / fileRuleChurnWarning

Added value: +{
+  "oneOf": [
+    {
+      "additionalProperties": false,
+      "properties": {
+        "checkCount": {
+          "type": "integer"
+        },
+        "file": {
+          "type": "string"
+        },
+        "hint": {
+          "type": "string"
+        },
+        "rule": {
+          "type": "string"
+        }
+      },
+      "required": [
+        "file",
+        "rule",
+        "checkCount",
+        "hint"
+      ],
+      "type": "object"
+    },
+    {
+      "type": "null"
+    }
+  ]
+}

changedOutput schema / properties / schemaVersion / enum

Previous value: -[
-  "1.1"
-]New value: +[
+  "1.2"
+]

Changed1 schema field changedv0.3.7Aug 19, 2026

changedOutput schema / (root)

Previous value: -nullNew value: +{
+  "properties": {
+    "clusters": {
+      "items": {
+        "additionalProperties": false,
+        "properties": {
+          "clusterId": {
+            "type": "string"
+          },
+          "fileCount": {
+            "type": "integer"
+          },
+          "issueCount": {
+            "type": "integer"
+          },
+          "priority": {
+            "type": "integer"
+          },
+          "rootCauseSummary": {
+            "type": "string"
+          },
+          "ruleIds": {
+            "items": {
+              "type": "string"
+            },
+            "type": "array"
+          },
+          "sampleIssueIds": {
+            "items": {
+              "type": "string"
+            },
+            "type": "array"
+          },
+          "suggestedAction": {
+            "type": "string"
+          }
+        },
+        "required": [
+          "clusterId",
+          "rootCauseSummary",
+          "ruleIds",
+          "issueCount",
+          "fileCount",
+          "priority",
+          "suggestedAction",
+          "sampleIssueIds"
+        ],
+        "type": "object"
+      },
+      "type": "array"
+    },
+    "code": {
+      "type": "string"
+    },
+    "engine": {
+      "enum": [
+        "oxlint",
+        "tsc",
+        "biome"
+      ],
+      "type": "string"
+    },
+    "engines": {
+      "additionalProperties": false,
+      "properties": {
+        "biome": {
+          "additionalProperties": false,
+          "properties": {
+            "message": {
+              "type": "string"
+            },
+            "status": {
+              "enum": [
+                "ok",
+                "error",
+                "disabled"
+              ],
+              "type": "string"
+            }
+          },
+          "required": [
+            "status"
+          ],
+          "type": "object"
+        },
+        "oxlint": {
+          "additionalProperties": false,
+          "properties": {
+            "message": {
+              "type": "string"
+            },
+            "status": {
+              "enum": [
+                "ok",
+                "error",
+                "disabled"
+              ],
+              "type": "string"
+            }
+          },
+          "required": [
+            "status"
+          ],
+          "type": "object"
+        },
+        "tsc": {
+          "additionalProperties": false,
+          "properties": {
+            "message": {
+              "type": "string"
+            },
+            "status": {
+              "enum": [
+                "ok",
+                "error",
+                "disabled"
+              ],
+              "type": "string"
+            }
+          },
+          "required": [
+            "status"
+          ],
+          "type": "object"
+        }
+      },
+      "required": [
+        "oxlint",
+        "tsc",
+        "biome"
+      ],
+      "type": "object"
+    },
+    "loopWarning": {
+      "oneOf": [
+        {
+          "additionalProperties": false,
+          "properties": {
+            "hint": {
+              "type": "string"
+            },
+            "occurrences": {
+              "type": "integer"
+            },
+            "signature": {
+              "type": "string"
+            }
+          },
+          "required": [
+            "signature",
+            "occurrences",
+            "hint"
+          ],
+          "type": "object"
+        },
+        {
+          "type": "null"
+        }
+      ]
+    },
+    "message": {
+      "type": "string"
+    },
+    "schemaVersion": {
+      "enum": [
+        "1.1"
+      ],
+      "type": "string"
+    },
+    "status": {
+      "enum": [
+        "clean",
+        "issues_found",
+        "timeout",
+        "error"
+      ],
+      "type": "string"
+    },
+    "totalIssues": {
+      "type": "integer"
+    },
+    "truncated": {
+      "type": "boolean"
+    }
+  },
+  "required": [
+    "status"
+  ],
+  "type": "object"
+}

First observedv0.3.3Aug 8, 2026

TDQS

A4.9/5.0

Behavior5/5

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

Annotations already declare readOnly/idempotent/non-destructive, yet the description adds substantial non-obvious behavior: content-hash-based caching, the rule that re-checks trigger on content or config-file changes rather than git status, and the caveat that TypeScript is whole-program and re-runs when any TS file in the request changes. That is rich context beyond the structured fields.

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

Conciseness5/5

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

Front-loaded with the action and safety, then usage routing, then parameter constraints, then caching nuances. Each sentence carries distinct, load-bearing information with no filler.

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?

An output schema exists so return values need not be explained; combined with annotations covering safety and the description covering usage, parameter constraints, and caching semantics, an agent has everything needed to invoke this correctly.

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

Parameters4/5

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

Schema description coverage is 0%, so the description must carry semantics, and it does: 'files' expects relative paths within the project directory, rejects globs/absolute/out-of-root paths with an error, and is bounded in practice by the checking model. It adds real meaning beyond the bare array type, though it does not restate the maxItems limit.

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?

Names specific verbs and resources — Oxlint and TypeScript lint/type diagnostics on a specific list of files — and immediately distinguishes itself from the sibling check_project by scoping to files rather than the whole project.

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

Usage Guidelines5/5

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

Explicit routing: 'Use this for incremental checks after editing specific files; use check_project for a full project scan.' It also states the exclusion for the files parameter (no globs, no absolute paths) and the error consequence, leaving nothing to inference.

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

Deploy Server