Optimize tool descriptions for token efficiency (#73)

* Optimize background-task tool descriptions for token efficiency

- BACKGROUND_TASK_DESCRIPTION: 571 chars → 127 chars
- BACKGROUND_OUTPUT_DESCRIPTION: 268 chars → 95 chars
- BACKGROUND_CANCEL_DESCRIPTION: 374 chars → 83 chars

Follows token efficiency improvements pattern from PR #71.

🤖 Generated with assistance of OhMyOpenCode (https://github.com/code-yeongyu/oh-my-opencode)

* Optimize call-omo-agent tool description for token efficiency

- CALL_OMO_AGENT_DESCRIPTION: 841 chars → 156 chars (~81% reduction)
- Follows pattern from PR #71 where LSP tool descriptions were optimized
- Maintains core information while removing redundant explanations

🤖 Generated with assistance of OhMyOpenCode (https://github.com/code-yeongyu/oh-my-opencode)

* Optimize look-at tool description for token efficiency

🤖 Generated with assistance of OhMyOpenCode (https://github.com/code-yeongyu/oh-my-opencode)

* Optimize interactive-bash tool description for token efficiency

346 chars → 130 chars (~62% reduction), following PR #71 pattern.

🤖 Generated with assistance of OhMyOpenCode

src/tools/look-at/constants.ts

@@ -1,10 +1,3 @@
 export const MULTIMODAL_LOOKER_AGENT = "multimodal-looker" as const
 
-export const LOOK_AT_DESCRIPTION = `Analyze media files (PDFs, images, diagrams) that require visual interpretation.
-
-Parameters:
-- file_path: Absolute path to the file to analyze
-- goal: What specific information to extract (be specific for better results)
-
-This tool uses a separate context window with Gemini 2.5 Flash for multimodal analysis,
-saving tokens in the main conversation while providing accurate visual interpretation.`
+export const LOOK_AT_DESCRIPTION = `Analyze media files (PDFs, images, diagrams) via Gemini 2.5 Flash in separate context. Saves main context tokens.`