Your cover note is arguably as important as the resume of the person you are sending. The manager will read this and will likely read it before they open the resume - it also helps Hirechain quickly review candidates. When writing a cover note this is what you should address:
Why do you think this person is a good fit for the role?
Bad Example: "Good candidate with great skills”
Good Example: “This candidate has recently been leading a defi platform on arbitrum and has exposure to all of the key skills your client is looking for - they have recent hands on solidity experience and can work in the timezones required”
Why would the client potentially reject the candidate? Address these upfront.
Does the candidate have gaps in their resume?
Is their job title currently CTO even though they want a hands on job?
Face potential issues head on and address them - if you think they are the person for the job then make sure any possible push backs are dealt with. Managers are busy and they don’t have time to go back and forth 5 times on every candidate.