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coinbase_portfolio_snapshot

Read balances and open orders directly from Coinbase Advanced Trade DOM, providing a read-only portfolio snapshot without using APIs.

Instructions

Read balances + open orders directly from the Advanced Trade DOM (never from an API), using the discovered selectors with a stability-ranked fallback chain. Read-only.

Tool call template

This tool declares no required parameters. Add optional parameters from the input schema as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {},
    "name": "coinbase_portfolio_snapshot"
  }
}

Input Schema

Name	Required	Description	Default
`debugUrl`	No		http://127.0.0.1:9222
`urlContains`	No

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.2.0Jul 12, 2026

TDQS

B3.4/5.0

Behavior3/5

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

With no annotations, the description carries full burden. It mentions 'read-only' and a 'stability-ranked fallback chain' but does not detail failure modes, required permissions, or the implications of the fallback chain. Partial transparency but missing critical behavioral context.

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?

The description is concise at two sentences and front-loaded with the primary action. However, the term 'stability-ranked fallback chain' is jargon that could be simplified without losing meaning.

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

Completeness2/5

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

Given no output schema and minimal annotations, the description should provide a complete picture. It lacks details on the output format, scope of data (e.g., all accounts?), and behavior of the fallback chain. Incomplete for an agent to reliably invoke.

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

Parameters2/5

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

Schema description coverage is 0%, and the tool description adds no explanation for the two parameters (debugUrl, urlContains). The agent must rely on parameter names and defaults, which is insufficient for correct usage.

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?

The description clearly states the action ('Read') and the specific resource ('balances + open orders') from a defined source ('Advanced Trade DOM'). It distinguishes itself from API-based tools by emphasizing 'never from an API', making its purpose unambiguous.

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

Usage Guidelines3/5

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

The description implies usage for real-time DOM data but does not explicitly specify when to use this tool over siblings like coinbase_market_stream or coinbase_paper_ledger. No when-not-to-use or alternative guidance is provided.

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