Intervals.icu MCP Server

get_activity_interval_stats

Calculate aggregate stats for a chosen index range in an activity's data streams using start and end positions; useful for analyzing a slice, not listing intervals.

Instructions

Compute aggregate stats for an index range of an activity's data streams.

start_index/end_index are positions in the activity's streams (as seen in the
streams or interval output). This computes metrics for that slice — it does NOT
list the activity's own intervals (use get_activity_intervals for that).

Args:
    activity_id: The Intervals.icu activity ID.
    start_index: Start position in the activity streams (required).
    end_index: End position in the activity streams (required, > start_index).

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "activity_id": "<activity_id>",
      "start_index": "<start_index>",
      "end_index": "<end_index>"
    },
    "name": "get_activity_interval_stats"
  }
}

Input Schema

Name	Required	Description	Default
`end_index`	Yes
`activity_id`	Yes
`start_index`	Yes

Output Schema

Name	Required	Description	Default
`result`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.3.0Nov 2, 2026

TDQS

A4.1/5.0

Behavior3/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

No annotations are supplied, so the description carries the burden; 'compute' implies a read-only operation but that is never stated, nor is any cost/rate behavior. It does add useful behavioral context about what the indices mean and the constraint end_index > start_index, which is more than the schema gives.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness4/5

Is the description appropriately sized, front-loaded, and free of redundancy?

Front-loaded with the core purpose and the sibling exclusion before the Args block; there is minor redundancy between the prose and the Args list, but no sentence is wasted.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness4/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With three required params at 0% schema coverage and no annotations, the description supplies the semantics and constraints an agent needs; an output schema exists so return values need not be described. Only the read-only/non-destructive nature is left implicit.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters4/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 0% and the schema only offers bare titles, yet the Args block explains activity_id as the Intervals.icu activity ID and locates start_index/end_index as positions in the activity's streams with the ordering constraint. This meaningfully compensates for the undocumented schema.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb and resource ('compute aggregate stats for an index range of an activity's data streams') and explicitly contrasts itself with get_activity_intervals, so an agent can distinguish it from the similar-sounding sibling without inspecting either schema.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines4/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

Explicitly says what the tool does NOT do and names the alternative (get_activity_intervals) for that case. It does not address the other nearby siblings (get_activity_streams, get_activity_details), leaving some routing ambiguity, but the main confusion pair is handled.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.