wording

README.md

@@ -125,7 +125,7 @@ empty commit to the PR*.
 | `description`              | No       | `Concourse CI build failed`          | The description status on the specified pull request.                                                                                                         |
 | `description_file`         | No       | `my-output/description.txt`          | Path to file containing the description status to add to the pull request                                                                                     |
 | `delete_previous_comments` | No       | `true`                               | Boolean. Previous comments made on the pull request by this resource will be deleted before making the new comment. Useful for removing outdated information. |
-| `delete_comment_tag`       | No       | `Summary`                            | String. An optional substring to match when deleting previous comments made on the pull request to avoid deleting all the comments made by the same user.     |
+| `delete_comment_tag`       | No       | `Summary`                            | String. A substring can be specified to match when deleting previous comments on a pull request, to avoid deleting all comments made by the same user.        |
 
 Note that `comment`, `comment_file` and `target_url` will all expand environment variables, so in the examples above `$ATC_EXTERNAL_URL` will be replaced by the public URL of the Concourse ATCs.
 See https://concourse-ci.org/implementing-resource-types.html#resource-metadata for more details about metadata that is available via environment variables.