Intervals.icu MCP Server

update_sport_settings

Change an athlete's FTP, LTHR, or threshold pace for a specific sport after explicit approval, updating the values that drive load, intensity, and zone calculations.

Instructions

⚠️ Change the athlete's training thresholds (FTP, LTHR, pace) for one sport.

These values drive ALL future load, intensity and zone calculations across
Intervals.icu. Do NOT call this speculatively — show the athlete the exact
old→new values and get their explicit approval first.

This is a confirmed write. On clients that support MCP elicitation you will be
prompted to approve the change; otherwise you MUST pass ``confirm=True`` after the
athlete has agreed. Without confirmation the tool refuses and returns the diff.

Args:
    settings_id: The sport-settings record ID (from get_sport_settings).
    ftp: New FTP in watts.
    indoor_ftp: New indoor FTP in watts.
    w_prime: New W' in joules.
    lthr: New lactate-threshold HR in bpm.
    max_hr: New max HR in bpm.
    threshold_pace: New threshold pace (in the sport's pace units).
    recalc_hr_zones: If True, ask Intervals.icu to recompute HR zones from the new LTHR/max HR.
    confirm: Set True to confirm the change on clients without elicitation support.

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": {
      "settings_id": "<settings_id>"
    },
    "name": "update_sport_settings"
  }
}

Input Schema

Name	Required	Description	Default
`ftp`	No
`lthr`	No
`max_hr`	No
`confirm`	No
`w_prime`	No
`indoor_ftp`	No
`settings_id`	Yes
`threshold_pace`	No
`recalc_hr_zones`	No

Output Schema

Name	Required	Description	Default
`result`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.3.0Nov 2, 2026

TDQS

A4.6/5.0

Behavior4/5

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

With no annotations, the description carries the full burden and does so well: it declares a confirmed write, describes elicitation prompting, and states that an unconfirmed call is refused and returns a diff. It does not state what happens to parameters left null (unchanged vs. cleared) or any permission/auth requirements, which are the remaining gaps.

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

Conciseness5/5

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

The warning and confirmation requirement are front-loaded ahead of the Args list, and the Args block is scannable. Sentences carry operational consequences rather than filler.

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?

Output schema exists, so return-shape explanation is unnecessary, and the refusal/diff behavior is noted anyway. For a 9-parameter mutation this is close to complete, missing only null-vs-omitted semantics and whether the change is reversible.

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%, so the Args block does the real work: every one of the 9 parameters is documented with units (watts, joules, bpm, sport's pace units) and, for recalc_hr_zones and confirm, the behavioral effect. It does not clarify null semantics for the optional threshold fields, which matters given all defaults are null.

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 — changes training thresholds (FTP, LTHR, pace) for a single sport — and explains downstream impact on load/zone calculations. An agent can distinguish this from get_sport_settings or update_wellness without opening any schema.

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

Usage Guidelines5/5

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

Explicitly says not to call speculatively, requires showing old→new values and getting athlete approval, and names the prerequisite source for settings_id (get_sport_settings). It also states the fallback path when elicitation is unavailable.

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