Ted Yoo and Krishen Singh write "Notes to Patent Drafters: Common Issues with Broad Specifications in Canada" in the PCT Network. They say:

Like all aspects of patent law, the requirement for a full and complete description to support the entire scope of broad claims presents opportunities and pitfalls for patent practitioners.  We must steer between Scylla representing insufficient description, which could result in only narrow claims to specific examples being valid, while avoiding Charybdis representing a description which obscures the invention with overly broad or ambiguous statements, or which introduces unnecessary essentiality to some preferred embodiments.

Read the full article in the PCT Network website.