The phrase "at first eager" is correct and usable in written English.
It can be used to describe someone's initial enthusiasm or willingness before a change in attitude or circumstances occurs.
Example: "At first eager to participate in the project, she soon lost interest when the workload became overwhelming."
Alternatives: "initially enthusiastic" or "first excited".
Dayton, at first eager for publicity, now feels made laughing stock by Scopes trial.
Foreign governments were at first eager to lend Pontin up to 50% of his building costs, at modest interest rates over 15 to 20 years.
It's the inner journey of a man who is at first eager to learn as much as he can from service and scholarship.
If anything, he was a little tougher on the boys at first, eager to quash any thoughts of favoritism.
When I reached him by phone in custody, he at first seemed eager to discuss what he called his "agency relationships".
It seemed all in fun at first, an eager little rag with classy, Deco-tinged covers, barely afloat from week to week, but already a habit in younger households.
(Minister blesses foxhounds, runs hill and dale, blesses fox, too). It seemed all in fun at first, an eager little rag with classy, Deco-tinged covers, barely afloat from week to week, but already a habit in younger households.
The person added, "What he wants to do is get back to taxes, make sure the Senate gets that done as soon as possible". Aides said that Trump knew that those who privately supported his endorsement of Strange, such as White House chief of staff John F. Kelly, were doing so because Trump at first was eager to do so and saw a chance to patch up relationships in Congress.
Children took the occasion to ask their questions, and were at first very eager to learn about the conditions of living in the station.
That's the Upper East Side for you: snooty at first, but ultimately eager to please.
His intention was encouraged by the new Soviet government, which at first showed itself eager to win the favour and services of avant-garde artists.
