Community orders can include unpaid work
A "chronic lack" of data on community orders - an alternative to jail - could damage public confidence, say MPs.
No-one knows how many orders have been completed and it is difficult to gauge their impact on reoffending, they said.
The Commons public accounts committee urged ministers to provide more data on their effectiveness to courts, which sometimes see them as a "soft option".
Community orders in England and Wales range from anger management courses or drug rehabilitation to unpaid work.
The MPs' report said sentences served in the community, introduced in 2003, did offer a "credible alternative to custody".
The committee's Conservative chairman, Edward Leigh, said they could be a "tough option" but there was a "long way to making them as effective as they could be".
There was little information available to the courts about who might best benefit from a community order, rather than a short jail sentence, the committee said.
And the reconviction rate - the most popular measure of re-offending - did not include all crimes committed in the two-year monitoring period after sentencing, they said.
Some people with drink problems were not ordered to attend treatment schemes because there were not enough available locally.
Although 25% of criminals' actions were thought to be fuelled by alcohol misuse, only 2% were given an alcohol treatment order, MPs noted.
"This means that the cause of offending may not be being tackled effectively," MPs said.
Some courts saw community sentences as a "soft option" and were less likely to hand them down as a result.
The committee urged ministers to do more to promote them as a "real alternative", by using case examples and local data on the proportions of orders completed and breached.
It also suggested promoting and "increasing the visibility" of unpaid work such as litter clearance and chewing gum removal, which accounted for 31% of all community orders.
Mr Leigh added: "There is a chronic lack of information about community sentences.
"It does nothing for confidence in community orders, among both sentencers and the public, if no-one knows how many have been completed by offenders."
A National Audit Office report in January noted that some people on community orders were allowed to miss meetings if they overslept, or had no transport.
The committee said there was a danger that variations in the way community orders were enforced in different areas could damage confidence.
It said local performance data should be published and proper implementation of standards encouraged "particularly those relating to acceptable absences and the completion of orders".
A spokesman for crime reduction charity Nacro welcomed the recommendation that the government should promote community orders as an alternative to jail.
Harry Fletcher, of probation union Napo, added: "The Ministry of Justice needs to demonstrate its commitment to community penalties by publishing relevant data on its effectiveness."
"It should also conduct an audit of community programmes and invest in those which show significant reductions in re-offending or the reduced seriousness of offences."