diff --git a/crates/pod/src/feature/plugin.rs b/crates/pod/src/feature/plugin.rs
index dd2774cf..c8d58190 100644
--- a/crates/pod/src/feature/plugin.rs
+++ b/crates/pod/src/feature/plugin.rs
@@ -184,6 +184,7 @@ pub fn inspect_resolved_plugin_static(record: &ResolvedPluginRecord) -> PluginSt
         })
         .collect();
 
+    let duplicate_tool_names = duplicate_tool_names(record);
     let tools = record
         .manifest
         .tools
@@ -192,9 +193,11 @@ pub fn inspect_resolved_plugin_static(record: &ResolvedPluginRecord) -> PluginSt
             let permission = PluginPermission::tool(&tool.name);
             let requested = permission_requested(record, &permission);
             let granted = grant_allows(record, &permission);
-            let diagnostic = authorize_plugin_tool(record, tool)
-                .err()
-                .map(|error| error.bounded_message());
+            let mut diagnostics = validate_plugin_tool_definition(tool, &duplicate_tool_names);
+            if let Err(error) = authorize_plugin_tool(record, tool) {
+                diagnostics.push(error.bounded_message());
+            }
+            let diagnostic = join_tool_diagnostics(diagnostics);
             PluginToolEligibility {
                 name: tool.name.clone(),
                 permission: permission.label(),
@@ -230,6 +233,48 @@ fn grant_allows(record: &ResolvedPluginRecord, permission: &PluginPermission) ->
         .any(|granted| granted == permission)
 }
 
+fn duplicate_tool_names(record: &ResolvedPluginRecord) -> HashSet<String> {
+    let mut seen = HashSet::new();
+    let mut duplicates = HashSet::new();
+    for tool in &record.manifest.tools {
+        if !seen.insert(tool.name.clone()) {
+            duplicates.insert(tool.name.clone());
+        }
+    }
+    duplicates
+}
+
+fn validate_plugin_tool_definition(
+    tool: &PluginToolManifest,
+    duplicate_tool_names: &HashSet<String>,
+) -> Vec<String> {
+    let mut diagnostics = Vec::new();
+    if duplicate_tool_names.contains(&tool.name) {
+        diagnostics.push(format!(
+            "tool `{}` has duplicate name within plugin manifest",
+            tool.name
+        ));
+    }
+    if let Err(reason) = validate_tool_name(&tool.name) {
+        diagnostics.push(format!("tool `{}` has invalid name: {reason}", tool.name));
+    }
+    if let Err(reason) = validate_input_schema(&tool.input_schema) {
+        diagnostics.push(format!(
+            "tool `{}` has invalid input_schema: {reason}",
+            tool.name
+        ));
+    }
+    diagnostics
+}
+
+fn join_tool_diagnostics(diagnostics: Vec<String>) -> Option<String> {
+    if diagnostics.is_empty() {
+        None
+    } else {
+        Some(bounded_message(diagnostics.join("; ")))
+    }
+}
+
 impl FeatureModule for PluginToolFeature {
     fn descriptor(&self) -> FeatureDescriptor {
         let mut descriptor =
@@ -1860,6 +1905,70 @@ input_schema = { type = "object", additionalProperties = true }
         );
     }
 
+    #[test]
+    fn static_inspection_reports_invalid_tool_definition() {
+        let mut bad_schema = tool("Echo");
+        bad_schema.input_schema = json!({"type":"string"});
+        let mut record = record(vec![bad_schema]);
+        record.manifest.runtime = Some(PluginRuntimeManifest {
+            kind: "wasm".to_string(),
+            entry: "plugin.wasm".to_string(),
+            abi: Some("yoi-plugin-wasm-1".to_string()),
+        });
+
+        let inspection = inspect_resolved_plugin_static(&record);
+
+        assert!(!inspection.statically_eligible());
+        assert!(!inspection.tools[0].eligible);
+        let diagnostic = inspection.tools[0]
+            .diagnostic
+            .as_deref()
+            .unwrap_or_default();
+        assert!(diagnostic.contains("invalid input_schema"));
+        assert!(diagnostic.contains("root schema type must be `object`"));
+    }
+
+    #[test]
+    fn static_inspection_reports_invalid_and_duplicate_tool_names() {
+        let mut invalid = tool("Bad Tool");
+        invalid.input_schema = json!({"type":"object"});
+        let mut first_duplicate = tool("Echo");
+        let mut second_duplicate = tool("Echo");
+        first_duplicate.input_schema = json!({"type":"object"});
+        second_duplicate.input_schema = json!({"type":"object"});
+        let mut record = record(vec![invalid, first_duplicate, second_duplicate]);
+        record.manifest.runtime = Some(PluginRuntimeManifest {
+            kind: "wasm".to_string(),
+            entry: "plugin.wasm".to_string(),
+            abi: Some("yoi-plugin-wasm-1".to_string()),
+        });
+
+        let inspection = inspect_resolved_plugin_static(&record);
+
+        assert!(!inspection.statically_eligible());
+        assert!(
+            inspection.tools[0]
+                .diagnostic
+                .as_deref()
+                .unwrap_or_default()
+                .contains("invalid name")
+        );
+        assert!(
+            inspection.tools[1]
+                .diagnostic
+                .as_deref()
+                .unwrap_or_default()
+                .contains("duplicate name")
+        );
+        assert!(
+            inspection.tools[2]
+                .diagnostic
+                .as_deref()
+                .unwrap_or_default()
+                .contains("duplicate name")
+        );
+    }
+
     fn write_stored_zip(path: &Path, files: &[(&str, &[u8])]) {
         let mut out = Vec::new();
         let mut central = Vec::new();
diff --git a/crates/yoi/src/plugin_cli.rs b/crates/yoi/src/plugin_cli.rs
index 6382b1a8..26f540d9 100644
--- a/crates/yoi/src/plugin_cli.rs
+++ b/crates/yoi/src/plugin_cli.rs
@@ -989,6 +989,64 @@ mod tests {
         );
     }
 
+    #[test]
+    fn invalid_tool_schema_and_name_are_rejected_in_json_and_human_output() {
+        let dir = tempdir().unwrap();
+        let workspace = dir.path();
+        let bad_schema_manifest = plugin_manifest("bad_schema", "Echo", "string", &["Echo"]);
+        let bad_name_manifest = plugin_manifest("bad_name", "Bad Tool", "object", &["Bad Tool"]);
+        let bad_schema_digest =
+            write_plugin_manifest(workspace, "bad_schema", &bad_schema_manifest);
+        let bad_name_digest = write_plugin_manifest(workspace, "bad_name", &bad_name_manifest);
+        let mut config = PluginConfig::default();
+        config.enabled.push(enablement(
+            "project:bad_schema",
+            "0.1.0",
+            bad_schema_digest,
+            &["Echo"],
+        ));
+        config.enabled.push(enablement(
+            "project:bad_name",
+            "0.1.0",
+            bad_name_digest,
+            &["Bad Tool"],
+        ));
+
+        let snapshot = inspect_snapshot(workspace, &config);
+        let bad_schema = select_item(&snapshot, "project:bad_schema").unwrap();
+        let bad_name = select_item(&snapshot, "project:bad_name").unwrap();
+
+        assert_eq!(bad_schema.status, "rejected");
+        assert_eq!(bad_name.status, "rejected");
+        assert!(!bad_schema.tools[0].eligible);
+        assert!(!bad_name.tools[0].eligible);
+
+        let list_json = serde_json::to_value(&snapshot).unwrap();
+        assert!(list_json["items"].as_array().unwrap().iter().any(|item| {
+            item["reference"] == "project:bad_schema"
+                && item["status"] == "rejected"
+                && item["tools"][0]["diagnostic"]
+                    .as_str()
+                    .unwrap_or_default()
+                    .contains("invalid input_schema")
+        }));
+        let show_json = serde_json::to_value(bad_name).unwrap();
+        assert_eq!(show_json["status"], "rejected");
+        assert!(
+            show_json["tools"][0]["diagnostic"]
+                .as_str()
+                .unwrap_or_default()
+                .contains("invalid name")
+        );
+
+        let list_output = render_list_snapshot_human(&snapshot).unwrap();
+        assert!(list_output.contains("project:bad_schema [rejected]"));
+        assert!(list_output.contains("project:bad_name [rejected]"));
+        let show_output = render_item_human(bad_schema).unwrap();
+        assert!(show_output.contains("invalid input_schema"));
+        assert!(show_output.contains("eligible=false"));
+    }
+
     #[test]
     fn ambiguous_ref_is_bounded_error() {
         let snapshot = PluginInspectionSnapshot {
@@ -1042,6 +1100,66 @@ mod tests {
         }
     }
 
+    fn enablement(
+        id: &str,
+        version: &str,
+        digest: String,
+        tool_permissions: &[&str],
+    ) -> PluginEnablementConfig {
+        let mut permissions = vec![PluginPermission::surface(PluginSurface::Tool)];
+        permissions.extend(
+            tool_permissions
+                .iter()
+                .map(|tool_name| PluginPermission::tool(*tool_name)),
+        );
+        PluginEnablementConfig {
+            id: id.to_string(),
+            digest: Some(digest.clone()),
+            version: Some(PluginExactVersion(version.to_string())),
+            surfaces: vec![PluginSurface::Tool],
+            grants: PluginGrantConfig {
+                id: Some(id.to_string()),
+                version: Some(PluginExactVersion(version.to_string())),
+                digest: Some(digest),
+                permissions,
+            },
+            config: None,
+        }
+    }
+
+    fn plugin_manifest(
+        id: &str,
+        tool_name: &str,
+        schema_type: &str,
+        permission_tools: &[&str],
+    ) -> String {
+        let permissions = permission_tools
+            .iter()
+            .map(|tool| format!(r#"{{ kind = "tool", name = "{tool}" }}"#))
+            .collect::<Vec<_>>()
+            .join(", ");
+        format!(
+            r#"
+schema_version = 1
+id = "{id}"
+name = "{id}"
+version = "0.1.0"
+surfaces = ["tool"]
+permissions = [{{ kind = "surface", surface = "tool" }}, {permissions}]
+
+[runtime]
+kind = "wasm"
+entry = "plugin.wasm"
+abi = "yoi-plugin-wasm-1"
+
+[[tools]]
+name = "{tool_name}"
+description = "Test tool"
+input_schema = {{ type = "{schema_type}" }}
+"#
+        )
+    }
+
     fn write_plugin_package(workspace: &Path, id: &str) -> String {
         let manifest = format!(
             r#"