This one is not particularly an agile behavior, just a good practice. When you need to ask someone for something, make it easy on the person you need something from. Make sure your request is well-formed. By “well-formed” I mean that the request has all of the information necessary to complete the request. I should also request a confirmation that the person will do the request.
A well-formed request should have the following parts.
State what you want. 
This is the request. Be specific in what you want. Do not make the person guess at what you need. In a poorly-formed request, this is all that someone gets and it is usually not very specific.
State how you want it.
This is the form of the reply that you are expecting. This could be an e-mail, a report, a spreadsheet, even a simple “tell me what you find out” form.
State when you want it.
This is the timeframe in which you need the request to be completed. In addition to dates and times, “By Friday noon” and “before you leave today” are examples of timeframes. If you request a date, be sure to indicate a timeframe. Friday 8:00 am and Friday 5:00 pm are two very different interpretations of “on Friday”.
Indicate the priority of the request.
“High”, “Medium”, and “Low” are always good indicators. However, if every request you make is “high” priority, you lose all credibility in the “Is this really important” department. If you know the person’s work list, you can say what the request is more important than or less important than.

Ask if this works for the person you are making the request?
This gives the person a chance to ask questions about the request. It also gives them an opportunity to assess the request against all of the other work they need to complete. If they say yes, you have an implicit commitment that they will do what was asked.  If not, you can answer questions or reframe or adjust the request to be more acceptable. You can negotiation an agreeable request. Sometimes though, the person just cannot fulfill your request. But now you know so that you are not expecting something to be done when nothing is happening.

Yes, making a well-formed request takes more time on your part. But, by taking the time, you will usually save time in the long run. By making a well-formed request, you…
1. Improve the odds that the request will be handled to you satisfaction.
2. Make it easier on the person by providing defined response criteria.
3. Show respect for the person’s current work and autonomy.