This paper discusses the conception and establishment of the descriptive and thematic representation activities as well as the specialized vocabulary control in the website Embrapa Information Agency (IEA).It is adopted the standard Dublin Core for metadata description of the information resources, which are represented by the minimum rules for cataloging and indexing. Specializing thesauri are adopted in agriculture for assigning keywords and subject categories. Free terms control is assured, aiming vocabulary consistency and quality maintenance. It uses handling tools for information resources of vocabulary control, integrated to the management system content, which houses the activities set of the IEA website information organization. Activities that involve thematic and descriptive representation should be supported by procedures and tools that systematize and standardize their routines in order to ensure improvement in information retrieval.