This change updates the system prompt to conditionally include
`grep`-related instructions based on whether the `grep` tool is enabled.
Implementation details:
1. Add a `has_tool` handlebars helper.
2. Pass the `model` to all locations where the prompt is built.
3. Use `{{#if has_tool "grep"}}` in the system prompt to gate
`grep`-specific instructions.
Testing:
- Unit tests for the `hasTool` helper.
- Unit tests to verify that `grep`-related instructions are included /
omitted from the prompt as appropriate.
- Manual agent evaluation:
- Setup: Asked the Agent "List all impls of MyTrait in the project"
using a custom "No tools" profile (all tools disabled).
- Before the change: The Agent attempted to call `grep`, encountered an
error, then realized the tool was unavailable.
- After the change: The Agent immediately asked to enable a search tool.
Note: in principle, `grep`/`read_file` tool descriptions alone might be
enough, but to confirm this we need more evaluation. If it turns out to
be true, we'll be able to remove grep-specific instructions from the
system prompt and undo this change.
Release Notes:
- N/A
99df1190a9