docs: update guardrails, thread-safety, and resource-lifecycle pages for PR #1514 architectural fixes

docs/best-practices/agent-retry-strategies.mdx

@@ -898,6 +898,40 @@ async def test_hedged_requests():
     assert call_count == 2  # Both requests started
 ```
 
+## Built-in Task Guardrail Retries
+
+PraisonAI provides built-in retry functionality specifically for guardrail validation failures, distinct from the generic `ExponentialBackoffRetry` patterns above.
+
+<Note>
+Guardrail retries are handled automatically by the executor when `Task(guardrail=..., max_retries=...)` is configured. This is separate from manual retry implementations.
+</Note>
+
+```python
+from praisonaiagents import Agent, Task, PraisonAIAgents
+
+def validate_content(output):
+    """Built-in guardrail with retry support"""
+    if len(output.raw.split()) < 50:
+        return False, "Content too short - needs at least 50 words"
+    return True, output
+
+task = Task(
+    description="Write a detailed explanation",
+    agent=agent,
+    guardrail=validate_content,
+    max_retries=3,  # Built-in executor-level retry
+    retry_with_feedback=True
+)
+
+# The executor automatically handles:
+# - Guardrail validation
+# - Retry logic on failure  
+# - Feedback to agent on retry
+# - Final failure after max_retries
+```
+
+This differs from manual retry strategies as it's integrated into the task execution workflow and handles the retry loop at the executor level.
+
 ## Conclusion
 
 Implementing robust retry strategies is essential for building resilient multi-agent systems. By choosing the appropriate retry pattern and configuring it correctly, you can handle transient failures gracefully while avoiding issues like retry storms and cascading failures.

docs/best-practices/memory-cleanup.mdx

@@ -89,6 +89,19 @@ class MemoryEfficientConversationManager:
 
 ### 2. Agent Memory Management
 
+Memory construction is now thread-safe and async-safe. Concurrent `Task`s sharing a `memory_config` will coordinate through locks rather than each creating duplicate stores.
+
+```python
+from praisonaiagents import Agent, Task, PraisonAIAgents
+
+memory_config = {"storage": {"path": "./shared.db"}, "provider": "file"}
+
+agents  = [Agent(name=f"A{i}", instructions="Summarize one line.") for i in range(4)]
+tasks   = [Task(description=f"Summarize doc {i}.", agent=agents[i], config={"memory_config": memory_config}) for i in range(4)]
+
+PraisonAIAgents(agents=agents, tasks=tasks).start()
+```
+
 Implement memory limits and cleanup for agents:
 
 ```python
@@ -371,6 +384,24 @@ class AutomaticMemoryManager:
         schedule.every(5).minutes.do(conditional_cleanup)
 ```
 
+### 3. Agent Garbage Collection Safety Net
+
+Since PR #1514, `Agent.__del__` runs a best-effort `close_connections()` during garbage collection as a safety net. However, this may be skipped by the Python interpreter and **must not be relied upon**. Always use explicit cleanup:
+
+```python
+# Preferred: Explicit cleanup
+agent = Agent(name="Analyst", instructions="Analyze data.")
+try:
+    result = agent.start("Analyze quarterly numbers.")
+finally:
+    agent.close()  # Guaranteed cleanup
+
+# Better: Context manager (recommended)  
+with Agent(name="Analyst", instructions="Analyze data.") as agent:
+    result = agent.start("Analyze quarterly numbers.")
+# Cleanup happens automatically here
+```
+
 ## Best Practices
 
 ### 1. Use Context Managers

docs/features/guardrails.mdx

@@ -254,7 +254,7 @@ guardrail = LLMGuardrail(
 
 ### Retry Configuration
 
-Configure retry behaviour for failed validations:
+Configure retry behaviour for failed validations (works in both sync and async execution paths):
 
 ```python
 task = Task(
@@ -267,6 +267,35 @@ task = Task(
 )
 ```
 
+**Execution Order**: Guardrail validation → retry (if failed) or pass → memory/user callbacks → task marked `completed`.
+
+### How Retries Work
+
+When a guardrail validation fails:
+1. **Before PR #1514**: Async execution bypassed retry logic
+2. **After PR #1514**: Both sync and async execution paths properly retry failed validations
+
+The executor increments `task.retry_count`, sets `task.status = "in progress"`, logs the retry, and continues the execution loop. On final failure after `max_retries`, it raises an exception. When a guardrail returns a modified `TaskOutput` or string, the downstream `task.result` and any memory callbacks receive the **modified** value, not the original.
+
+```python
+from praisonaiagents import Agent, Task, PraisonAIAgents
+
+def must_mention_price(output):
+    ok = "$" in output.raw
+    return (ok, output if ok else "Rewrite and include a price in USD.")
+
+agent = Agent(name="Writer", instructions="Write a one-line product blurb.")
+
+task = Task(
+    description="Write a blurb for a coffee mug.",
+    agent=agent,
+    guardrail=must_mention_price,
+    max_retries=3,
+)
+
+PraisonAIAgents(agents=[agent], tasks=[task]).start()
+```
+
 ### Composite Guardrails
 
 Combine multiple validation criteria:

docs/features/resource-lifecycle.mdx

@@ -83,6 +83,7 @@ sequenceDiagram
     User->>Team: (exit with block)
     Team->>Agents: close() each
     Team->>Memory: close()
+    Note right of Memory: Closes SQLite, MongoDB, etc.
     Team-->>User: cleanup complete
 ```
 
@@ -208,6 +209,21 @@ async with PraisonAIAgents(agents=[agent]) as workflow:
 ```
 </Accordion>
 
+<Accordion title="MongoDB connections are now included in cleanup">
+Since PR #1514, `Memory.close_connections()` also closes MongoDB clients when present. Multiple calls to `close_connections()` are safe (idempotent). Agent `__del__` provides a safety net but should not be relied upon:
+
+```python
+# Explicit cleanup (preferred)
+with Agent(name="Analyst", instructions="Analyze quarterly numbers.") as agent:
+    agent.start("Summarize Q1 revenue.")
+# MongoDB / SQLite / registered connections closed here.
+
+# Async form  
+async with Agent(name="Analyst", instructions="...") as agent:
+    await agent.astart("...")
+```
+</Accordion>
+
 <Accordion title="Don't reuse a team after exiting its with block">
 Once you exit a `with` block, consider the AgentTeam closed. Create a new one for additional work.
 

docs/features/thread-safety.mdx

@@ -53,6 +53,18 @@ Prior to PR #1488, chat_history mutations bypassed thread-safety locks at 31+ ca
 - `chat_history` setter now acquires the `AsyncSafeState` lock for assignments
 </Note>
 
+#### What changed in PR #1514
+
+<Note>
+PR #1514 enhanced thread-safety in three key areas:
+
+**1. Locked Memory Initialization**: `Task.initialize_memory()` now uses `threading.Lock` with double-checked locking pattern. A new async variant `initialize_memory_async()` uses `asyncio.Lock` and offloads construction with `asyncio.to_thread()` to prevent event loop blocking.
+
+**2. Async-Locked Workflow State**: New `_set_workflow_finished(value)` method uses async locks to safely update workflow completion status across concurrent tasks.
+
+**3. Non-Mutating Task Context**: Task execution no longer mutates `task.description` during runs. Per-execution context is stored in `_execution_context` field, keeping the user-facing `task.description` stable across multiple executions.
+</Note>
+
 #### Safe operations
 
 ```python