fix(inference/ollama): use prompt-guided tool calling so skills work on Ollama (#3098 sub-issue 3)

src/openhuman/inference/provider/compatible.rs

@@ -80,6 +80,14 @@ pub struct OpenAiCompatibleProvider {
     /// carries an `@<temp>` suffix (e.g. `"openai:gpt-4o@0.2"`). The
     /// `temperature_unsupported_models` glob filter still applies after.
     pub(crate) temperature_override: Option<f64>,
+    /// Value reported by `capabilities().native_tool_calling`. Defaults to
+    /// `true` because most OpenAI-compatible providers (OpenAI, Anthropic
+    /// adapters, GLM, Groq, Mistral, OpenHuman backend, …) implement the
+    /// `tools` parameter correctly. The factory flips this to `false` for
+    /// Ollama (sub-issue 3 of #3098), whose OpenAI-compat endpoint returns
+    /// HTTP 400 on `tools` for many models — making prompt-guided text
+    /// tool specs the only path that works across the Ollama model zoo.
+    native_tool_calling: bool,
 }
 
 /// How the provider expects the API key to be sent.
@@ -195,9 +203,20 @@ impl OpenAiCompatibleProvider {
             emit_openhuman_thread_id: false,
             temperature_unsupported_models: Vec::new(),
             temperature_override: None,
+            native_tool_calling: true,
         }
     }
 
+    /// Toggle whether this provider advertises native (OpenAI-style) tool
+    /// calling to the agent harness. The default is `true`; set to `false`
+    /// for providers whose `/v1/chat/completions` endpoint rejects the
+    /// `tools` parameter — the harness will then embed tool specs in the
+    /// system prompt and parse calls out of the response text instead.
+    pub fn with_native_tool_calling(mut self, enabled: bool) -> Self {
+        self.native_tool_calling = enabled;
+        self
+    }
+
     /// Set the list of model glob patterns for which temperature must be
     /// omitted from request bodies. Called by the provider factory to
     /// propagate `config.temperature_unsupported_models`.
@@ -1248,7 +1267,7 @@ impl OpenAiCompatibleProvider {
 impl Provider for OpenAiCompatibleProvider {
     fn capabilities(&self) -> crate::openhuman::inference::provider::traits::ProviderCapabilities {
         crate::openhuman::inference::provider::traits::ProviderCapabilities {
-            native_tool_calling: true,
+            native_tool_calling: self.native_tool_calling,
             vision: false,
         }
     }
@@ -1940,7 +1959,12 @@ impl Provider for OpenAiCompatibleProvider {
     }
 
     fn supports_native_tools(&self) -> bool {
-        true
+        // Must mirror `capabilities().native_tool_calling`. Both signals are
+        // read by the agent harness (`traits.rs:415`) to decide between an
+        // OpenAI-style `tools` array and the prompt-guided text fallback;
+        // letting them disagree would defeat `with_native_tool_calling(false)`
+        // for the Ollama branch of sub-issue 3 of #3098.
+        self.native_tool_calling
     }
 
     fn supports_streaming(&self) -> bool {

src/openhuman/inference/provider/compatible_tests.rs

@@ -1303,6 +1303,69 @@ fn capabilities_reports_native_tool_calling() {
     assert!(caps.native_tool_calling);
 }
 
+// Sub-issue 3 of #3098: Ollama's OpenAI-compat endpoint silently rejects the
+// `tools` parameter for many models, so we must let the factory opt the
+// Ollama provider out of native tool calling. The agent harness then falls
+// back to prompt-guided tool specs (embedded in the system prompt) which
+// any chat model can follow. The builder defaults to enabled so cloud
+// providers (OpenAI, BYOK slugs, OpenHuman backend) are unaffected.
+
+#[test]
+fn with_native_tool_calling_false_disables_capability() {
+    let p = make_provider("test", "https://example.com", None).with_native_tool_calling(false);
+    let caps = <OpenAiCompatibleProvider as Provider>::capabilities(&p);
+    assert!(
+        !caps.native_tool_calling,
+        "capabilities() must mirror the builder override; this is the gate the agent harness uses to decide between native vs prompt-guided tool specs"
+    );
+}
+
+#[test]
+fn with_native_tool_calling_true_preserves_default() {
+    let p = make_provider("test", "https://example.com", None).with_native_tool_calling(true);
+    let caps = <OpenAiCompatibleProvider as Provider>::capabilities(&p);
+    assert!(caps.native_tool_calling);
+}
+
+#[test]
+fn with_native_tool_calling_is_idempotent() {
+    let p = make_provider("test", "https://example.com", None)
+        .with_native_tool_calling(false)
+        .with_native_tool_calling(false);
+    let caps = <OpenAiCompatibleProvider as Provider>::capabilities(&p);
+    assert!(!caps.native_tool_calling);
+}
+
+/// `supports_native_tools()` is the gate the agent harness reads
+/// (`traits.rs:415`) when deciding whether to send tools natively or
+/// inject them into the prompt. It MUST agree with
+/// `capabilities().native_tool_calling`; otherwise
+/// `with_native_tool_calling(false)` silently fails to switch to
+/// prompt-guided and Ollama still receives a `tools` array (the exact
+/// regression sub-issue 3 of #3098 was meant to fix).
+#[test]
+fn supports_native_tools_mirrors_capabilities_flag() {
+    let default = make_provider("test", "https://example.com", None);
+    assert_eq!(
+        default.supports_native_tools(),
+        <OpenAiCompatibleProvider as Provider>::capabilities(&default).native_tool_calling,
+        "default provider: the two capability signals must match"
+    );
+    assert!(default.supports_native_tools(), "default must remain true");
+
+    let opted_out =
+        make_provider("test", "https://example.com", None).with_native_tool_calling(false);
+    assert_eq!(
+        opted_out.supports_native_tools(),
+        <OpenAiCompatibleProvider as Provider>::capabilities(&opted_out).native_tool_calling,
+        "after with_native_tool_calling(false): the two capability signals must match"
+    );
+    assert!(
+        !opted_out.supports_native_tools(),
+        "after with_native_tool_calling(false), supports_native_tools must report false so the harness picks the prompt-guided fallback"
+    );
+}
+
 #[test]
 fn tool_specs_convert_to_openai_format() {
     let specs = vec![crate::openhuman::tools::ToolSpec {

src/openhuman/inference/provider/factory.rs

@@ -731,16 +731,24 @@ fn make_ollama_provider(
     // Ollama does not expose the Responses API (/v1/responses) — passing
     // `false` prevents a guaranteed-404 fallback attempt and the Sentry
     // noise it would generate (TAURI-RUST-59Y).
-    let p = make_openai_compatible_provider_with_config(
+    //
+    // Ollama also rejects the OpenAI-style `tools` parameter for many models
+    // (HTTP 400 "unsupported parameter: tools"), so we disable
+    // `native_tool_calling` on the provider directly. The agent harness
+    // then embeds tool specs in the system prompt and parses tool calls
+    // out of the response text — a format any chat model can follow.
+    // Skills that depend on tool invocations now work over Ollama
+    // (sub-issue 3 of #3098).
+    let provider = OpenAiCompatibleProvider::new_no_responses_fallback(
         "ollama",
         &endpoint,
-        "",
+        None,
         CompatAuthStyle::None,
-        &config.temperature_unsupported_models,
-        temperature_override,
-        false,
-    )?;
-    Ok((p, model.to_string()))
+    )
+    .with_temperature_unsupported_models(config.temperature_unsupported_models.clone())
+    .with_temperature_override(temperature_override)
+    .with_native_tool_calling(false);
+    Ok((Box::new(provider), model.to_string()))
 }
 
 /// Build an LM Studio local provider.

src/openhuman/inference/provider/factory_tests.rs

@@ -210,6 +210,48 @@ fn ollama_prefix() {
     assert_eq!(model, "llama3.1:8b");
 }
 
+#[test]
+fn ollama_provider_opts_out_of_native_tool_calling() {
+    // Sub-issue 3 of #3098: Ollama's OpenAI-compat endpoint returns HTTP 400
+    // for many models when a `tools` array is sent (the existing detection
+    // path matches "unsupported parameter: tools"). The retry logic strips
+    // tools entirely, which silently breaks any skill or workflow that
+    // depends on tool calls. The factory must build the Ollama provider
+    // with native tool calling disabled so the agent harness uses the
+    // prompt-guided text format from the first request.
+    let config = Config::default();
+    let (provider, _model) = create_chat_provider_from_string("chat", "ollama:llama3.2", &config)
+        .expect("ollama:<model> must build");
+    let caps = provider.capabilities();
+    assert!(
+        !caps.native_tool_calling,
+        "ollama provider must report native_tool_calling=false so the agent harness emits prompt-guided tool specs instead of an OpenAI-style `tools` array"
+    );
+}
+
+#[test]
+fn lmstudio_provider_keeps_native_tool_calling_enabled() {
+    // LM Studio's OpenAI-compat endpoint supports the `tools` parameter for
+    // models that expose function calling. Only Ollama gets opted out by
+    // default — the LM Studio path stays on the native schema.
+    let mut config = Config::default();
+    config.local_ai.base_url = Some("http://127.0.0.1:1234".to_string());
+    let (provider, _model) =
+        create_chat_provider_from_string("chat", "lmstudio:google/gemma-4-e4b", &config)
+            .expect("lmstudio:<model> must build");
+    assert!(
+        provider.capabilities().native_tool_calling,
+        "lmstudio provider must keep native_tool_calling=true; only the ollama branch opts out"
+    );
+}
+
+// Note: a BYOK-cloud regression test (e.g. `openai:gpt-4o` keeps
+// native_tool_calling=true) would need an `AuthService` with the slug's API
+// key seeded. The unit test
+// `with_native_tool_calling_true_preserves_default` in compatible_tests.rs
+// already pins that the builder leaves the default in place when not
+// called, which is what every non-Ollama factory path relies on.
+
 #[test]
 fn lmstudio_prefix() {
     let mut config = Config::default();