twelvebit Analytics

Add a chart annotation

add_annotation

Add a note to the site's time charts, like a launch, a deploy or a price change, so later changes in traffic or revenue can be explained. ts defaults to now. Pass idempotency_key so that a retry does not add the note twice.

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": {
      "label": "<label>"
    },
    "name": "add_annotation"
  }
}

Input Schema

Name	Required	Description
`ts`	No	ISO date or date-time. Default now.
`url`	No
`site`	No	Site domain (example.com), id or public id (tb_…). Optional with a site key, or when the account has one site.
`label`	Yes
`idempotency_key`	No	A fresh UUID for this create. Send the same value when you retry the same call: the first result comes back and nothing is created twice.

Schema Changelog

Changes observed during successful MCP inspections.

First observedOct 23, 2026

TDQS

A4/5.0

Behavior4/5

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

Annotations already declare non-read-only, non-destructive, and non-idempotent behavior, and the description adds the timestamp default and explicit retry-safe guidance via idempotency_key. That retry semantics detail is genuinely useful context not captured by idempotentHint=false.

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?

Three tight sentences: what it does, why, then two operational notes (ts default, retry safety). The use case is front-loaded and nothing is repeated from the schema.

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?

For a simple create tool with no output schema, the description covers purpose, default timestamp behavior, and retry safety. Minor gaps—required label emphasis and site/url usage—are largely handled by the schema itself.

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

Parameters3/5

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

At 60% schema coverage, the description reinforces the ts default and explains the purpose of idempotency_key beyond the schema's wording. However, it says nothing about the required label, the url, or site resolution, leaving a meaningful part of the parameter surface to the schema alone.

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

Purpose4/5

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

States a specific verb and resource ("Add a note to the site's time charts") with concrete examples (launch, deploy, price change) that clarify what an annotation is. The Add-vs-update/delete/list distinction is implicit in the sibling names but never stated.

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?

Gives a clear use case—marking events so later traffic or revenue shifts can be explained—which tells the agent when this tool applies. It stops short of naming alternatives such as update_annotation for existing notes or list_annotations for reading them.

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

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