From 1b1917e342be1eaeedc2bd20243bf3860fa70bcc Mon Sep 17 00:00:00 2001
From: Dmitry Zhuravlev <dmitry.zhuravlev@jetbrains.com>
Date: Sun, 8 Mar 2026 16:22:33 +0100
Subject: [PATCH] IJPL-233396 misc [mcp-server]: improve
 execute_run_configuration output for agent consumption

Default truncation kept the beginning of output (build logs) and
discarded the end (test failures, stack traces). Switch default to
TruncateMode.END.
When truncation occurs, write full output to a temp file and return
its path so agents can read_file the complete log.

(cherry picked from commit 1ebbed734bb85d1d2d2e343da0c3a8c0aadfa6fe)

GitOrigin-RevId: a964ca4b7dcb288481ddd75d996ff5c15a8c5e48
---
 .../toolsets/general/ExecutionToolset.kt      | 32 ++++++++++++++++---
 1 file changed, 27 insertions(+), 5 deletions(-)

diff --git a/plugins/mcp-server/src/com/intellij/mcpserver/toolsets/general/ExecutionToolset.kt b/plugins/mcp-server/src/com/intellij/mcpserver/toolsets/general/ExecutionToolset.kt
index 6aeb56771342..6a9452fe511b 100644
--- a/plugins/mcp-server/src/com/intellij/mcpserver/toolsets/general/ExecutionToolset.kt
+++ b/plugins/mcp-server/src/com/intellij/mcpserver/toolsets/general/ExecutionToolset.kt
@@ -24,6 +24,7 @@ import com.intellij.mcpserver.util.TruncateMode
 import com.intellij.mcpserver.util.checkUserConfirmationIfNeeded
 import com.intellij.mcpserver.util.truncateText
 import com.intellij.openapi.application.EDT
+import com.intellij.openapi.application.PathManager
 import com.intellij.openapi.application.readAction
 import com.intellij.openapi.diagnostic.logger
 import com.intellij.openapi.diagnostic.rethrowControlFlowException
@@ -37,6 +38,7 @@ import kotlinx.coroutines.withTimeoutOrNull
 import kotlinx.serialization.EncodeDefault
 import kotlinx.serialization.ExperimentalSerializationApi
 import kotlinx.serialization.Serializable
+import java.nio.file.Files
 import kotlin.time.Duration.Companion.milliseconds
 
 private val logger = logger<ExecutionToolset>()
@@ -157,14 +159,31 @@ class ExecutionToolset : McpToolset {
         mcpFail("Execution failed: ${e.message}")
       }
     }
-    val output = truncateText(outputBuilder.toString(), maxLinesCount = maxLinesCount, truncateMode = truncateMode)
+    val fullOutput = outputBuilder.toString()
+    val output = truncateText(fullOutput, maxLinesCount = maxLinesCount, truncateMode = truncateMode)
+    val fullOutputPath = if (output.length != fullOutput.length) createTmpFile(fullOutput) else null
+
     return RunConfigurationResult(
       exitCode = exitCode,
       timedOut = exitCode == null,
-      output = output
+      output = output,
+      fullOutputPath = fullOutputPath,
     )
   }
 
+  private fun createTmpFile(fullOutput: String): String? {
+    return try {
+      val tmpFile = Files.createTempFile(PathManager.getTempDir(), "run-config-output", ".log")
+      Files.writeString(tmpFile, fullOutput)
+      tmpFile.toAbsolutePath().toString()
+    }
+    catch (e: Exception) {
+      rethrowControlFlowException(e)
+      logger.trace { "Failed to write full output to temp file: ${e.message}" }
+      null
+    }
+  }
+
   @Serializable
   data class RunConfigurationsList(
     val configurations: List<RunConfigurationInfo>,
@@ -184,12 +203,15 @@ class ExecutionToolset : McpToolset {
   )
 
   @Serializable
-  data class RunConfigurationResult(
+  data class RunConfigurationResult @JvmOverloads constructor(
     @EncodeDefault(mode = EncodeDefault.Mode.NEVER)
     val exitCode: Int? = null,
     @property:McpDescription(Constants.TIMED_OUT_DESCRIPTION)
     @EncodeDefault(mode = EncodeDefault.Mode.NEVER)
     val timedOut: Boolean? = false,
-    val output: String
+    val output: String,
+    @property:McpDescription("Path to a temp file containing the full untruncated output. Present only when output was truncated. Use read_file to access the complete log.")
+    @EncodeDefault(mode = EncodeDefault.Mode.NEVER)
+    val fullOutputPath: String? = null,
   )
-}
\ No newline at end of file
+}