1  /**
 2   * Constants related to tool result size limits
 3   */
 4  
 5  /**
 6   * Default maximum size in characters for tool results before they get persisted
 7   * to disk. When exceeded, the result is saved to a file and the model receives
 8   * a preview with the file path instead of the full content.
 9   *
10   * Individual tools may declare a lower maxResultSizeChars, but this constant
11   * acts as a system-wide cap regardless of what tools declare.
12   */
13  export const DEFAULT_MAX_RESULT_SIZE_CHARS = 50_000
14  
15  /**
16   * Maximum size for tool results in tokens.
17   * Based on analysis of tool result sizes, we set this to a reasonable upper bound
18   * to prevent excessively large tool results from consuming too much context.
19   *
20   * This is approximately 400KB of text (assuming ~4 bytes per token).
21   */
22  export const MAX_TOOL_RESULT_TOKENS = 100_000
23  
24  /**
25   * Bytes per token estimate for calculating token count from byte size.
26   * This is a conservative estimate - actual token count may vary.
27   */
28  export const BYTES_PER_TOKEN = 4
29  
30  /**
31   * Maximum size for tool results in bytes (derived from token limit).
32   */
33  export const MAX_TOOL_RESULT_BYTES = MAX_TOOL_RESULT_TOKENS * BYTES_PER_TOKEN
34  
35  /**
36   * Default maximum aggregate size in characters for tool_result blocks within
37   * a SINGLE user message (one turn's batch of parallel tool results). When a
38   * message's blocks together exceed this, the largest blocks in that message
39   * are persisted to disk and replaced with previews until under budget.
40   * Messages are evaluated independently — a 150K result in one turn and a
41   * 150K result in the next are both untouched.
42   *
43   * This prevents N parallel tools from each hitting the per-tool max and
44   * collectively producing e.g. 10 × 40K = 400K in one turn's user message.
45   *
46   * Overridable at runtime via GrowthBook flag tengu_hawthorn_window — see
47   * getPerMessageBudgetLimit() in toolResultStorage.ts.
48   */
49  export const MAX_TOOL_RESULTS_PER_MESSAGE_CHARS = 200_000
50  
51  /**
52   * Maximum character length for tool summary strings in compact views.
53   * Used by getToolUseSummary() implementations to truncate long inputs
54   * for display in grouped agent rendering.
55   */
56  export const TOOL_SUMMARY_MAX_LENGTH = 50