feat(tools/looker): Add description for looker-get-models tool (#1266)

…tool

## Description
---
Add description to output of get_models, as well as add output details
to docs

## PR Checklist
---
> Thank you for opening a Pull Request! Before submitting your PR, there
are a
> few things you can do to make sure it goes smoothly:
- [X] Make sure you reviewed

[CONTRIBUTING.md](https://github.com/googleapis/genai-toolbox/blob/main/CONTRIBUTING.md)
- [X] Make sure to open an issue as a

[bug/issue](https://github.com/googleapis/langchain-google-alloydb-pg-python/issues/new/choose)
before writing your code! That way we can discuss the change, evaluate
  designs, and agree on the general idea
- [X] Ensure the tests and linter pass
- [X] Code coverage does not decrease (if any source code was changed)
- [X] Appropriate docs were updated (if necessary)
- [X] Make sure to add `!` if this involve a breaking change

🛠️ Fixes #1246

docs/en/resources/tools/looker/looker-get-explores.md

@@ -21,6 +21,16 @@ It's compatible with the following sources:
 `looker-get-explores` accepts one parameter, the
 `model` id.
 
+The return type is an array of maps, each map is formatted like:
+
+```json
+{
+    "name": "explore name",
+    "description": "explore description",
+    "label": "explore label",
+    "group_label": "group label"
+}
+```
 ## Example
 
 ```yaml

internal/tools/looker/lookergetexplores/lookergetexplores.go

@@ -139,6 +139,9 @@ func (t Tool) Invoke(ctx context.Context, params tools.ParamValues, accessToken
 		if v.Name != nil {
 			vMap["name"] = *v.Name
 		}
+		if v.Description != nil {
+			vMap["description"] = *v.Description
+		}
 		if v.Label != nil {
 			vMap["label"] = *v.Label
 		}

tests/looker/looker_integration_test.go

@@ -621,7 +621,7 @@ func TestLooker(t *testing.T) {
 	wantResult := "{\"label\":\"System Activity\",\"name\":\"system__activity\",\"project_name\":\"system__activity\"}"
 	tests.RunToolInvokeSimpleTest(t, "get_models", wantResult)
 
-	wantResult = "{\"group_label\":\"System Activity\",\"label\":\"Content Usage\",\"name\":\"content_usage\"}"
+	wantResult = "{\"description\":\"Data about Look and dashboard usage, including frequency of views, favoriting, scheduling, embedding, and access via the API. Also includes details about individual Looks and dashboards.\",\"group_label\":\"System Activity\",\"label\":\"Content Usage\",\"name\":\"content_usage\"}"
 	tests.RunToolInvokeParametersTest(t, "get_explores", []byte(`{"model": "system__activity"}`), wantResult)
 
 	wantResult = "{\"description\":\"Number of times this content has been viewed via the Looker API\",\"label\":\"Content Usage API Count\",\"label_short\":\"API Count\",\"name\":\"content_usage.api_count\",\"synonyms\":[],\"tags\":[],\"type\":\"number\"}"