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 that the data is 'live' from a 'US-regulated crypto venue' and that 'Levels 1-3 control depth,' providing useful behavioral context beyond the annotations. No contradictions with annotations.

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 a single, front-loaded sentence with three concise clauses: what the tool provides, how a parameter works, and intended uses. Every phrase adds value without redundancy or filler.

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?

With only two parameters, an output schema present, and helpful annotations, the description covers purpose, parameters, and usage context in a compact manner. It mentions the venue's regulatory status and depth levels, leaving no critical gaps for an agent to select and invoke the tool correctly.

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 description coverage is 0%, so the description must explain parameters. It does so effectively: 'product_id' is clarified with examples like 'BTC-USD', and 'level' is explicitly said to control depth with values 1-3. This fully compensates for the lack of schema descriptions.

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 it provides a live order book with bids and asks for a crypto pair, explicitly naming Coinbase Exchange and example product IDs. This distinguishes it from sibling tools like product_trades, product_candles, and product_ticker by specifying the order book resource and its depth levels.

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 gives explicit use cases: 'spread analysis, liquidity assessment, market making.' While it doesn't name alternative tools or state when not to use it, the context is clear enough for an agent to determine when an order book is needed versus other market data tools.

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