diff --git a/docs/docs/tools/describe.md b/docs/docs/tools/describe.md
index 25b3c6fc..d8d074a6 100644
--- a/docs/docs/tools/describe.md
+++ b/docs/docs/tools/describe.md
@@ -59,17 +59,23 @@ Everything below this marker is treated as previously auto-generated content and
 ### Sequence Diagram Support 
 When the `enable_pr_diagram` option is enabled in your configuration, the `/describe` tool will include a `Mermaid` sequence diagram in the PR description.
 
-This diagram represents interactions between components/functions based on the diff content.
+This diagram represents interactions between components/functions based on the PR content.
 
-### How to enable
+[//]: # (### How to enable\disable)
 
-In your configuration:
+[//]: # ()
+[//]: # (In your configuration:)
 
-```
-toml
-[pr_description]
-enable_pr_diagram = true
-```
+[//]: # ()
+[//]: # (```)
+
+[//]: # (toml)
+
+[//]: # ([pr_description])
+
+[//]: # (enable_pr_diagram = true)
+
+[//]: # (```)
 
 ## Configuration options
 
@@ -126,7 +132,7 @@ enable_pr_diagram = true
       </tr>
       <tr>
         <td><b>enable_pr_diagram</b></td>
-        <td>If set to true, the tool will generate a horizontal Mermaid flowchart summarizing the main pull request changes. This field remains empty if not applicable. Default is false.</td>
+        <td>If set to true, the tool will generate a horizontal Mermaid flowchart summarizing the main pull request changes. This field remains empty if not applicable. Default is true.</td>
       </tr>
     </table>
 
diff --git a/pr_agent/settings/configuration.toml b/pr_agent/settings/configuration.toml
index f028c9f0..e3648fcc 100644
--- a/pr_agent/settings/configuration.toml
+++ b/pr_agent/settings/configuration.toml
@@ -106,7 +106,7 @@ enable_pr_type=true
 final_update_message = true
 enable_help_text=false
 enable_help_comment=true
-enable_pr_diagram=false # adds a section with a diagram of the PR changes
+enable_pr_diagram=true # adds a section with a diagram of the PR changes
 # describe as comment
 publish_description_as_comment=false
 publish_description_as_comment_persistent=true
diff --git a/pr_agent/settings/pr_description_prompts.toml b/pr_agent/settings/pr_description_prompts.toml
index 126fe771..d8954052 100644
--- a/pr_agent/settings/pr_description_prompts.toml
+++ b/pr_agent/settings/pr_description_prompts.toml
@@ -48,7 +48,7 @@ class PRDescription(BaseModel):
     description: str = Field(description="summarize the PR changes in up to four bullet points, each up to 8 words. For large PRs, add sub-bullets if needed. Order bullets by importance, with each bullet highlighting a key change group.")
     title: str = Field(description="a concise and descriptive title that captures the PR's main theme")
 {%- if enable_pr_diagram %}
-    changes_diagram: str = Field(description="a horizontal diagram that represents the main PR changes, in the format of a valid mermaid LR flowchart. The diagram should be concise and easy to read. Leave empty if no diagram is relevant. To create robust Mermaid diagrams, follow this two-step process: (1) Declare the nodes: nodeID["node description"]. (2) Then define the links: nodeID1 -- "link text" --> nodeID2 ")
+    changes_diagram: str = Field(description="a horizontal diagram that represents the main PR changes, in the format of a valid mermaid LR flowchart. The diagram should be concise and easy to read. Leave empty if no diagram is relevant. To create robust Mermaid diagrams, follow this two-step process: (1) Declare the nodes: nodeID["node description"]. (2) Then define the links: nodeID1 -- "link text" --> nodeID2. Node description must always be surrounded with quotation marks.")
 {%- endif %}
 {%- if enable_semantic_files_types %}
     pr_files: List[FileDescription] = Field(max_items=20, description="a list of all the files that were changed in the PR, and summary of their changes. Each file must be analyzed regardless of change size.")
diff --git a/pr_agent/tools/pr_description.py b/pr_agent/tools/pr_description.py
index 663c5a2d..c4595140 100644
--- a/pr_agent/tools/pr_description.py
+++ b/pr_agent/tools/pr_description.py
@@ -59,6 +59,7 @@ class PRDescription:
 
         # Initialize the variables dictionary
         self.COLLAPSIBLE_FILE_LIST_THRESHOLD = get_settings().pr_description.get("collapsible_file_list_threshold", 8)
+        enable_pr_diagram = get_settings().pr_description.get("enable_pr_diagram", False) and self.git_provider.is_supported("gfm_markdown") # github and gitlab support gfm_markdown
         self.vars = {
             "title": self.git_provider.pr.title,
             "branch": self.git_provider.get_pr_branch(),
@@ -73,7 +74,7 @@ class PRDescription:
             "related_tickets": "",
             "include_file_summary_changes": len(self.git_provider.get_diff_files()) <= self.COLLAPSIBLE_FILE_LIST_THRESHOLD,
             "duplicate_prompt_examples": get_settings().config.get("duplicate_prompt_examples", False),
-            "enable_pr_diagram": get_settings().pr_description.get("enable_pr_diagram", False),
+            "enable_pr_diagram": enable_pr_diagram,
         }
 
         self.user_description = self.git_provider.get_user_description()