From ae37f3ca2e7bcaa54491eb870743844ce5c16b7a Mon Sep 17 00:00:00 2001
From: Bennet Bo Fenner <bennet@zed.dev>
Date: Fri, 25 Apr 2025 15:14:16 +0200
Subject: [PATCH] agent: Improve MCP tools compatibility with Gemini models
 (#29411)

Release Notes:

- agent: Improve MCP tools compatibility with Gemini models
---
 crates/assistant_tool/src/tool_schema.rs | 39 +++++++++++++++++++++---
 1 file changed, 35 insertions(+), 4 deletions(-)

diff --git a/crates/assistant_tool/src/tool_schema.rs b/crates/assistant_tool/src/tool_schema.rs
index c7d7ba1c33..9d2711ecb1 100644
--- a/crates/assistant_tool/src/tool_schema.rs
+++ b/crates/assistant_tool/src/tool_schema.rs
@@ -35,7 +35,15 @@ fn adapt_to_json_schema_subset(json: &mut Value) -> Result<()> {
             }
         }
 
-        obj.remove("format");
+        const KEYS_TO_REMOVE: [&str; 4] = [
+            "format",
+            "additionalProperties",
+            "exclusiveMinimum",
+            "exclusiveMaximum",
+        ];
+        for key in KEYS_TO_REMOVE {
+            obj.remove(key);
+        }
 
         if let Some(default) = obj.get("default") {
             let is_null = default.is_null();
@@ -47,7 +55,7 @@ fn adapt_to_json_schema_subset(json: &mut Value) -> Result<()> {
         }
 
         // If a type is not specified for an input parameter, add a default type
-        if obj.contains_key("description")
+        if matches!(obj.get("description"), Some(Value::String(_)))
             && !obj.contains_key("type")
             && !(obj.contains_key("anyOf")
                 || obj.contains_key("oneOf")
@@ -119,14 +127,37 @@ mod tests {
                 "type": "string"
             })
         );
+
+        // Ensure that we do not add a type if it is an object
+        let mut json = json!({
+            "description": {
+                "value": "abc",
+                "type": "string"
+            }
+        });
+
+        adapt_to_json_schema_subset(&mut json).unwrap();
+
+        assert_eq!(
+            json,
+            json!({
+                "description": {
+                    "value": "abc",
+                    "type": "string"
+                }
+            })
+        );
     }
 
     #[test]
-    fn test_transform_removes_format() {
+    fn test_transform_removes_unsupported_keys() {
         let mut json = json!({
             "description": "A test field",
             "type": "integer",
-            "format": "uint32"
+            "format": "uint32",
+            "exclusiveMinimum": 0,
+            "exclusiveMaximum": 100,
+            "additionalProperties": false
         });
 
         adapt_to_json_schema_subset(&mut json).unwrap();