Best Efforts? Commercially Reasonable Efforts?

Words of caution if you ever use "efforts" clauses instead of unambiguous obligations.

Consider using such clause is the market/industry practice

Use the same terms consistently throughout the agreement

Consider dispute identification mechanism at a sign of dispute or disagreement as to performance

Include temporal limitations and certainty

Consider time frames for efforts including within specific number of days or months from a triggering date or event

Define efforts

Sample definitions in the context of M & A:

• "Efforts that a prudent Person desirous of achieving a result would use in similar circumstances to ensure that such result is achieved as expeditiously as possible on commercially reasonable terms."
• "Efforts that a prudent Person desirous of achieving a result would use in similar circumstances to achieve such result as expeditiously as possible; provided, however, that a Person required to use commercially reasonable efforts under this Agreement will not be required to take actions that would result in a material adverse change in the benefits to such Person of this Agreement and the transactions contemplated hereby or to dispose of or make any change to its business, expend any material funds or incur any other material burden."
• "Efforts consistent with the past practices of similarly situated [INDUSTRY] companies with respect to similarly situated [MATTER]"
• "Efforts consistent with the past practice of [PURCHASER] related to research and development, regulatory approval, commercialization and sales and marketing of similar [PRODUCTS] with similar market potential at a similar stage in development"

Include carve-outs as what efforts clause does not require of covenanting party

• Expense cap in dollar amounts on attorneys' fees and other costs
• Conduct that would reasonably be expected to have a material adverse effect on covenanting party
• Actions that would subject the covenanting party to liabilities
• Actions in contravention of law or regulatory requirements
• Actions that would impact profitability or solvency of the covenanting party
• Fiduciary outs (subject to break-up fee and other deal protections for the buyer)

HSR or other regulatory approvals

• Reverse break-up fee
• Ticking fees that increase based upon length of time it takes to address concerns
• Detailed efforts covenants identifying problematic lines of business or assets to be divested
• Negative covenants of buyer restricting pre-closing acquisition of assets or business or other actions that would exacerbate antitrust problems

Third Party Consents

• Control or specify the timing of pursuing consents, expenses in doing so, and thresholds for closing (must-have consents)
• Consider third party leverages 

Acquisition Financing

• "Buyer  shall, and shall cause its Affiliates to, use commercially reasonable efforts to obtain the Financing on the terms and conditions described in the Financing Letter, including using commercially reasonable efforts to (i) enter into definitive agreements with respect to the Financing (including agreeing to any requested changes to the Financing Letter by the committed lenders in accordance with the related flex provisions), (ii) satisfy (or obtain waiver) on a timely basis of all conditions in such definitive agreements (within buyer's control) and (iii) consummate the Financing contemplated by the Financing Letter at Closing."