estimate_tokens
Estimate the token count of a URL's content without performing a full fetch. This allows you to check if the content fits your remaining context window before deciding to retrieve it.
Instructions
Estimate token count of a URL's content WITHOUT fetching the body.
WHEN TO USE:
You're considering fetching a URL but unsure if it fits your remaining context window. This call is ~10x cheaper than a full fetch.
You want to triage a list of candidate URLs before deciding which to actually retrieve.
IMPORTANT: Many servers omit Content-Length on dynamic / chunked responses. When that happens, this tool returns confident=false and estimated_tokens=null. In that case, call fetch_url with a max_tokens cap instead of trusting the estimate.
Args: url: The URL to estimate.
Returns: { "url": str, "success": bool, "estimated_tokens": int | null, "byte_size": int | null, "content_type": str, "confident": bool, "note": str }
Input Schema
| Name | Required | Description | Default |
|---|---|---|---|
| url | Yes |