Polish agent prompts and fix wrong language instruction

Three related touch-ups to the three agent prompts:

- Fix a copy-paste bug where the Q&A and lint agents were told to
  "Write all wiki content in X language" — the Q&A agent doesn't write
  wiki content, and the lint agent writes reports. Switch them to
  "Answer in X" and "Write the lint report in X" respectively. The
  compiler agent keeps its original wording since it actually writes
  wiki content.

- Give all three agents an OpenKB identity in their opening line so
  the model introduces itself consistently when asked who it is.

- In the Q&A search strategy, finish the thought on summaries (tell
  the model to follow the `full_text` path when a summary is too
  thin), trim step 5 so the get_image tool's "when to call" guidance
  lives in the tool docstring instead of the instructions template,
  and reword step 5 to refer to the tool by name with "the ... tool".

Author: rejojer

openkb/agent/compiler.py

@@ -30,7 +30,7 @@
 # ---------------------------------------------------------------------------
 
 _SYSTEM_TEMPLATE = """\
-You are a wiki compilation agent for a personal knowledge base.
+You are OpenKB's wiki compilation agent for a personal knowledge base.
 
 {schema_md}
 

openkb/agent/linter.py

@@ -11,7 +11,7 @@
 from openkb.schema import SCHEMA_MD, get_agents_md
 
 _LINTER_INSTRUCTIONS_TEMPLATE = """\
-You are a knowledge-base semantic lint agent. Your job is to audit the wiki
+You are OpenKB's semantic lint agent. Your job is to audit the wiki
 for quality issues that structural tools cannot detect.
 
 {schema_md}
@@ -50,7 +50,7 @@ def build_lint_agent(wiki_root: str, model: str, language: str = "en") -> Agent:
     """
     schema_md = get_agents_md(Path(wiki_root))
     instructions = _LINTER_INSTRUCTIONS_TEMPLATE.format(schema_md=schema_md)
-    instructions += f"\n\nIMPORTANT: Write all wiki content in {language} language."
+    instructions += f"\n\nIMPORTANT: Write the lint report in {language} language."
 
     @function_tool
     def list_files(directory: str) -> str:

openkb/agent/query.py

@@ -12,25 +12,25 @@
 from openkb.schema import get_agents_md
 
 _QUERY_INSTRUCTIONS_TEMPLATE = """\
-You are a knowledge-base Q&A agent. You answer questions by searching the wiki.
+You are OpenKB, a knowledge-base Q&A agent. You answer questions by searching the wiki.
 
 {schema_md}
 
 ## Search strategy
 1. Read index.md to see all documents and concepts with brief summaries.
    Each document is marked (short) or (pageindex) to indicate its type.
 2. Read relevant summary pages (summaries/) for document overviews.
-   Note: summaries may omit details.
+   Summaries may omit details — if you need more, follow the summary's
+   `full_text` frontmatter field to the source (see step 4).
 3. Read concept pages (concepts/) for cross-document synthesis.
 4. When you need detailed source document content, each summary page has a
    `full_text` frontmatter field with the path to the original document content:
    - Short documents (doc_type: short): read_file with that path.
    - PageIndex documents (doc_type: pageindex): use get_page_content(doc_name, pages)
      with tight page ranges. The summary shows document tree structure with page
      ranges to help you target. Never fetch the whole document.
-5. When source content references images (e.g. ![image](sources/images/doc/file.png)),
-   use get_image to view them. Always view images when the question asks about
-   a figure, chart, diagram, or visual content.
+5. Source content may reference images (e.g. ![image](sources/images/doc/file.png)).
+   Use the get_image tool to view them when needed.
 6. Synthesize a clear, concise, well-cited answer grounded in wiki content.
 
 Answer based only on wiki content. Be concise.
@@ -44,7 +44,7 @@ def build_query_agent(wiki_root: str, model: str, language: str = "en") -> Agent
     """Build and return the Q&A agent."""
     schema_md = get_agents_md(Path(wiki_root))
     instructions = _QUERY_INSTRUCTIONS_TEMPLATE.format(schema_md=schema_md)
-    instructions += f"\n\nIMPORTANT: Write all wiki content in {language} language."
+    instructions += f"\n\nIMPORTANT: Answer in {language} language."
 
     @function_tool
     def read_file(path: str) -> str:
@@ -69,7 +69,10 @@ def get_page_content_tool(doc_name: str, pages: str) -> str:
     @function_tool
     def get_image(image_path: str) -> ToolOutputImage | ToolOutputText:
         """View an image from the wiki.
-        Use when source content references images you need to see.
+
+        Use when a question asks about a specific figure, chart, or diagram
+        you'd need to see to answer accurately.
+
         Args:
             image_path: Image path relative to wiki root (e.g. 'sources/images/doc/p1_img1.png').
         """