31,428 tokens before a word of yours.
With the tools option omitted, this SDK/runtime sent all 27 built-in tool definitions. Including them increased the estimated input by
29,645 tokens, or 94.3% of the captured total.
What filled the request before inference
Source: captured SDK request and Anthropic's official count_tokens endpoint
- Tools included 29,645 tokens · 94.3%
- Skill descriptions 1,486 tokens · 4.7%
- Base request 301 tokens · 1.0%
Scope
One isolated capture: SDK 0.3.168, runtime 2.1.168, model claude-opus-4-8, the tools and systemPrompt options omitted, settingSources: [], and no claude_code preset.
Reproduce
Every request, response, hash, package version, and measurement input is published for inspection.
Loaded context catalog
- Tool definitions
The built-in tool objects supplied to the request.
Items: 27 - Skill descriptions
Description metadata loaded up front; full SKILL.md bodies load only when invoked.
Items: 13 - Base request
What remains after removing tools and skill-description text.
Items: 6
Per-item token counts are independent comparison estimates. They rank items; they do not reconstruct the overview total.