A tool (10) for inserting a catheter (22) into a body of a patient is provided. The tool (10) comprises: a housing (12, 40, 50) in which at least a portion of the catheter (22) is initially disposed； a needle (16) distally extending from the housing (12, 40, 50), at least a portion of the catheter (22) disposed over the needle (16)； a guidewire (32) initially disposed within the needle (16) partially； and an advancement assembly (20) for distally advancing the catheter (22). The housing (12, 40, 50) comprises: a first portion (12A, 42, 52) comprising a distal part (42A, 52A) and a proximal part (42B)； and a second portion (12B, 44, 54) engaged with the first portion (12A, 42, 52), wherein the distal part (42A, 52A) of the first portion (12A, 42, 52) is configured to be able to distally slide with respect to the second portion (12B, 44, 54) to release the engagement between the first portion (12A, 42, 52) and the second portion (12B, 44, 54). The advancement assembly (20) includes a safety cap (26) which is initially disposed over the needle (16) and is configured to be locked to the housing (12, 40, 50) when distally sliding to a position of isolating the tip of the needle (16) within the safety cap (26).
