Mo. Rev. Stat. § 429.607

A lien notice, for purposes of sections 429.600 to 429.627, shall state the name of the claimant, the name of the owner, a description of the property upon which the lien is being claimed, the amount for which the lien is claimed, and the real estate license number of the real estate broker. The notice of lien shall be signed by the real estate broker and the broker shall attest that the information contained in the notice is true and accurate as to his knowledge and belief.