The rules text on traits is pretty clear. From the DH, p 80:
And here's what's said on pp 79, 80, 82, 177:
It is the player who invokes traits, via their action declarations. The player is expected to be creative, inventive and even surprising: the suggestions given in the trait list are just that; they are not prescriptions. This can include the GM, given that NPCs (but not monsters) have traits that the GM is able to invoke in their action declarations for those NPCs.
The group is expected to ensure that there is no "reaching": so it will be the interplay between the creativity of members and their sense of what does or doesn't fall under a given trait that will shape the meaning of various traits at a given table. Different tables will likely draw the boundaries and shape the meaning in different ways.
There's no unilateral GM power mentioned here. It is the player who invokes, and the GM can't deem the trait to have been invoked by a player's action declaration. (and thus consume a use, and modify a dice pool). And when the GM is playing a NPC, they can't unilaterally deem a trait to be appropriate: the rules are clear that this is the group's role. Similarly, the GM does not unilaterally police reaching. The group does this, as part of its judgements of appropriate uses.
There’s a phenomenon with traits that we call reaching. It’s a situation when a trait clearly doesn’t fit, but a player is working really hard to convince the group that it’ll work. This behavior is not creative. It’s just short of begging, and it’s certainly always bull.
If you feel a player is reaching, tell them so. Give them a moment to readjust. If they don’t have anything better to add, then move on. The trait doesn’t apply.
If you feel a player is reaching, tell them so. Give them a moment to readjust. If they don’t have anything better to add, then move on. The trait doesn’t apply.
And here's what's said on pp 79, 80, 82, 177:
When you want to use a trait to benefit a roll, describe your action and incorporate the trait into your narration. If the group feels it’s appropriate, take your trait benefit for that test.
Be creative with your traits. They are open to interpretation, so you can be inventive and surprise the other players with interesting descriptions of your character. . . .
If you can incorporate a trait into your description of your character’s actions so that it hinders you, you apply a penalty to your roll. . . .
Using traits against yourself allows you to demonstrate your character’s quirks and foibles. . . .
The following section describes each trait. The entries offer suggestions on how to use the trait, both to benefit your character and get them into trouble.
Be creative with your traits. They are open to interpretation, so you can be inventive and surprise the other players with interesting descriptions of your character. . . .
If you can incorporate a trait into your description of your character’s actions so that it hinders you, you apply a penalty to your roll. . . .
Using traits against yourself allows you to demonstrate your character’s quirks and foibles. . . .
The following section describes each trait. The entries offer suggestions on how to use the trait, both to benefit your character and get them into trouble.
It is the player who invokes traits, via their action declarations. The player is expected to be creative, inventive and even surprising: the suggestions given in the trait list are just that; they are not prescriptions. This can include the GM, given that NPCs (but not monsters) have traits that the GM is able to invoke in their action declarations for those NPCs.
The group is expected to ensure that there is no "reaching": so it will be the interplay between the creativity of members and their sense of what does or doesn't fall under a given trait that will shape the meaning of various traits at a given table. Different tables will likely draw the boundaries and shape the meaning in different ways.
There's no unilateral GM power mentioned here. It is the player who invokes, and the GM can't deem the trait to have been invoked by a player's action declaration. (and thus consume a use, and modify a dice pool). And when the GM is playing a NPC, they can't unilaterally deem a trait to be appropriate: the rules are clear that this is the group's role. Similarly, the GM does not unilaterally police reaching. The group does this, as part of its judgements of appropriate uses.