We've always told our clients that it's a good idea to review and compare homeowners' insurance every 3-4 years. Rates change, company policies change, and a company's overall risk experience can have dramatic effect on their policies.
At the suggestion of a property-casualty insurance colleague, we just increased our homeowner's liability coverage, doubling it to $1,000,000. The increase only cost us $4.60 per year. Might be worth talking to your insurance company. After all, a major injury on your property could easily involve medical bills, other expenses, and punitive damages exceeding $500,000. The increased coverage is dirt cheap and well worth it. Now about that half-dead tree that's overhanging the neighbor's house ...
Disclosure: Our company does not write property-casualty insurance. If you want recommendations, we can suggest some agents you might interview.