Instructions

Use this skill to verify task progress in an ALFWorld household environment. The skill is triggered after a key sub-action (e.g., put {obj} in/on {recep}) is performed.

1. Input Analysis

• •Input: The most recent Observation: from the environment following an action.
• •Task Goal: The original, full task description (e.g., "find two pen and put them in garbagecan").

2. Verification Logic

Analyze the observation to determine if the task's goal conditions are satisfied.

1. •Parse the Goal: Identify the target object(s) and the target receptacle from the task description.
2. •Check the Observation: Scrutinize the observation text for evidence that the required objects are present in the target receptacle.
   • •Positive evidence: Phrases like "you see a pen 3" located "in/on the garbagecan 1".
   • •The presence of other items in the receptacle does not invalidate success.
3. •Make a Decision:
   • •Task Complete: If the observation confirms all required objects are in the target receptacle. Output: "Verification: Task complete. No further action needed."
   • •Continue Task: If the observation shows some, but not all, required objects are in the target receptacle, or if the target object was just placed elsewhere. Output: "Verification: Task incomplete. Continue searching for [missing object(s)]."
   • •Action Invalid/No Change: If the observation is "Nothing happened" or does not reflect the intended outcome of the last action. Output: "Verification: Last action was ineffective. Re-assess and try a different approach."

3. Output

Output only the verification decision in the specified format. Do not output the next action. This skill informs the planning for the next action.

Example Outputs:

• •Verification: Task complete. No further action needed.
• •Verification: Task incomplete. Continue searching for pen 2.
• •Verification: Last action was ineffective. Re-assess and try a different approach.