Defense Minister Ezer Weizman announced today that Maj. Gen. Abraham Tamir would join the Israeli delegation at the Cairo conference next week. The inclusion of Tamir in the delegation is being interpreted here as a gesture to please the Egyptians, who had named a military man to their delegation.

A Foreign Office spokesman said Monday that there would be no military officer of the Israeli delegation because the delegation would not be authorized to discuss military or security matters in Cairo.

The primary mission of the delegation. Israeli officials said again today, would be to seek a "clarification of positions" - at least during the first stage of the negotiations. It was said that the Israeli delegation would concentrate on the broad nature of a possible peace agreement first rather than on more specific issues such as borders.

The inclusion of Gen. Tamir in the delegation may not signify a change in Israel's intentions during the first phase of the talks, but it does allow for a discussion of military and security matters that would not previously have been practical. As one official tonight said. "If you are going to talk at all about borders you have to have someone to represent the military."

Tamir is head of the planning branch of the general staff and he recently headed a team under the direction of Ezer Weizman to look into the military implications of President anwar Sadat's visit to Jerusalem.

The other two members of the Israeli delegation are Eliahu Ben Elissar, director general of the prime minister's office, and Meir Rosenne, legal advisor to the Foreign Ministry.

Sadat has hinted that he does considers the Israeli delegation to be too low-level and the Israelis have responded by saying they would strenghten the delegation to any level the Egyptians want if the Egyptians ask for a change.

It could not be confirmed that the Egyptians specifically asked for any change in the Israel delegation.