Michael Hammes brings us these 12 spells in a new 6-page PDF.
What are bothersome spells? Bothersome spells are spells that can be used to cause interesting and unique situations. Such spells don't cause any (or much) direct damage and, for most, their usefulness lies more in the imagination of the spellcaster than in the spell itself. Furthermore, such spells tend to frustrate those that suffer their effects rather than causing them harm directly.
Fireball is not a bothersome spell; it simply blasts creatures away. Animate rope, on the other hand, is a bothersome spell. In addition to tying a creature up, it can be used as a trip line, frustrating pursuit. Lightning bolt? Not bothersome. Grease? Bothersome. Disintegrate? Potentially bothersome. Bestow curse? Definitely bothersome. Mirror image? Very bothersome.
This PDF presents 12 spells in this vein. All have a quantifiable impact on the game, all can give the spellcaster and his or her allies some form of advantage, but these are not the kind of spells that are likely to kill outright, and many require some imagination to maximize their effectiveness.