By default, Entrez searches your text in "All fields", which looks for the text anywhere in the entry. So if you're getting irrelevant results, try limiting your text to a particular field.
Don't know what fields you can search for? Use the Advanced search.
1. Click on advanced beneath the search bar.
2. Click the drop down menu under Builder to see what fields are stored in gene records.
This is a comprehensive list of all fields you can search for. Fields will vary by database. Example shown here is for the Gene database.
In dbSNP, you can search by
These fields can be combined using Boolean operators to create refined search strategies for SNPs.
The results page for an individual SNP contains:
See the following link for an example