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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds context about the data source (US-regulated venue) and the type of data (current pricing), but does not disclose additional behaviors like rate limits or response quirks. This is adequate but not highly detailed.

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

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

The description is concise, with two sentences that front-load the core function and follow up with usage guidance. No wasted words.

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

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

For a simple one-parameter tool with good annotations and an output schema, the description is complete. It states what the tool does, why it exists, and when to use it, without leaving critical gaps.

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

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

Schema coverage is 0% for the product_id parameter, so the description must compensate. It does by describing the parameter's meaning as a 'crypto pair' on 'Coinbase-listed pair,' which aligns with the example 'BTC-USD' in the schema. This adds essential semantic context beyond the raw schema.

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

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

The description clearly states the tool provides best bid/ask, last trade price, and volume for a crypto pair on Coinbase Exchange. It uses specific verbs and a specific resource, distinguishing itself from sibling tools like product_book (order book), product_candles (historical candles), and product_trades (recent trades).

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

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

The description explicitly says 'Use for current pricing on a Coinbase-listed pair,' giving clear context for when to use it. However, it does not name alternatives or exclusions, such as suggesting product_candles for historical data.

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