fix: make cap unwrap text imply text output

docs/wf_cli.md

@@ -182,12 +182,12 @@ MCP content-block envelopes:
 wf cap call wf.std.constant --input '{"value": "hello"}' --format compact
 ```
 
-Use `--format text --unwrap-text` to extract exactly one MCP text content block.
-This mode refuses images, resources, blobs, multiple content blocks, and
+Use `--unwrap-text` to extract exactly one MCP text content block. This implies
+text output and refuses images, resources, blobs, multiple content blocks, and
 non-MCP output:
 
 ```bash
-wf cap call everything.default.echo --input '{"message": "hello"}' --format text --unwrap-text
+wf cap call everything.default.echo --input '{"message": "hello"}' --unwrap-text
 ```
 
 Use `--max-output-chars N` to bound compact/text terminal output. JSON output

src/wf_cli/commands/caps.py

@@ -12,6 +12,18 @@ from wf_cli.formats import ListOutputFormat, emit_list_payload
 from wf_cli.io import CliInputError, emit_json, parse_json_input
 from wf_cli.remote_errors import run_cli_operation
 
+CAP_CALL_HELP = """Call one workflow capability once for authoring/runtime smoke tests.
+
+Output modes:
+
+- json: Full lossless payload. Default. Never truncated.
+- compact: One bounded summary line.
+- text: Requires --unwrap-text and prints exactly one MCP text content block.
+
+Text unwrap refuses images, resources, blobs, multiple blocks, and non-MCP
+output. Use --max-output-chars to bound compact/text terminal output.
+"""
+
 
 class CapCallOutputFormat(StrEnum):
     JSON = "json"
@@ -80,7 +92,7 @@ def inspect_capability(
     emit_json(payload)
 
 
-@app.command("call")
+@app.command("call", help=CAP_CALL_HELP)
 def call_capability(
     ctx: typer.Context,
     qualified_name: Annotated[str, typer.Argument(help="Workflow capability name.")],
@@ -121,11 +133,10 @@ def call_capability(
         bool,
         typer.Option(
             "--unwrap-text",
-            help="Only with --format text: unwrap one MCP text block.",
+            help="Unwrap one safe MCP text block; implies --format text.",
         ),
     ] = False,
 ) -> None:
-    """Call one workflow capability once for authoring/runtime smoke tests."""
     try:
         payload = parse_json_input(input_json=input_json, input_file=input_file)
     except CliInputError as exc:
@@ -143,7 +154,10 @@ def call_capability(
     try:
         rendered = render_cap_call_output(
             result,
-            output_format=output_format,
+            output_format=_resolve_cap_call_output_format(
+                output_format=output_format,
+                unwrap_text=unwrap_text,
+            ),
             unwrap_text=unwrap_text,
             max_output_chars=max_output_chars,
         )
@@ -173,6 +187,17 @@ def render_cap_call_output(
     return _truncate_text(summary, max_output_chars=max_output_chars)
 
 
+def _resolve_cap_call_output_format(
+    *,
+    output_format: CapCallOutputFormat,
+    unwrap_text: bool,
+) -> CapCallOutputFormat:
+    """Treat --unwrap-text as the explicit request for safe text extraction."""
+    if unwrap_text and output_format is CapCallOutputFormat.JSON:
+        return CapCallOutputFormat.TEXT
+    return output_format
+
+
 def _compact_cap_call_summary(result: dict[str, Any]) -> str:
     output = result.get("output")
     output_summary = _summarize_output(output)

tests/wf_cli/test_caps.py

@@ -157,8 +157,6 @@ def test_cap_call_cli_unwraps_single_mcp_text_block(monkeypatch) -> None:
             "everything.default.echo",
             "--input",
             '{"message": "hello"}',
-            "--format",
-            "text",
             "--unwrap-text",
         ],
     )
@@ -191,6 +189,29 @@ def test_cap_call_cli_refuses_to_unwrap_blob_content(monkeypatch) -> None:
     assert "exactly one MCP text content block" in result.output
 
 
+def test_cap_call_cli_format_text_requires_unwrap_text(monkeypatch) -> None:
+    _patch_context(
+        monkeypatch,
+        _base_result({"content": [{"type": "text", "text": "hello text"}]}),
+    )
+
+    result = CliRunner().invoke(
+        app,
+        [
+            "cap",
+            "call",
+            "everything.default.echo",
+            "--input",
+            "{}",
+            "--format",
+            "text",
+        ],
+    )
+
+    assert result.exit_code != 0
+    assert "--format text requires --unwrap-text" in result.output
+
+
 def test_cap_call_cli_refuses_to_unwrap_multiple_text_blocks(monkeypatch) -> None:
     _patch_context(
         monkeypatch,

tests/wf_cli/test_remote_target.py

@@ -381,8 +381,11 @@ def test_wf_cap_commands_use_rpc_url_override(monkeypatch, tmp_path) -> None:
 
     help_result = runner.invoke(app, ["cap", "call", "--help"])
     assert help_result.exit_code == 0
+    help_text = " ".join(help_result.output.split())
     assert "--unwrap-text" in help_result.output
-    assert "MCP text block" in help_result.output
+    assert "MCP text content block" in help_text
+    assert "multiple blocks" in help_text
+    assert "non-MCP" in help_text
 
 
 def test_wf_source_commands_use_rpc_url_override(monkeypatch, tmp_path) -> None: