Show some infos about selected agents

[laeubi]

Describe the feature or problem you'd like to solve

Currently if one selects an agent it says something like "Selected custom agent: spec-writer"

Proposed solution

Each agent has a title and description. It would be useful to show these so one is sure to select the right agent.

Also the initial selection with /agent could likely benefit from showing the title instead of only the short form

Example prompts or workflows

No response

Additional context

No response