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

Annotations declare readOnlyHint and openWorldHint, so safety is already covered; the description adds the source scope (Binance/Bybit CEX only, not DEX pools) and the exact payload shape. It does not discuss rate limits or latency, but the exchange-coverage constraint is meaningful behavioral context beyond the 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?

Front-loaded with the core purpose, then clearly sectioned into use-when, not-for, returns, and an example. It is long but every block earns its place; the trailing price line is neutral noise rather than padding.

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 no output schema, the description carries the return-format burden and does so fully via a labeled 'Returns' list plus a concrete JSON example. Every sibling-routing and scope detail an agent needs to call this correctly is present.

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 100% and the single asset parameter is documented with examples in the schema itself. The description adds no syntax or format detail beyond that, so the baseline 3 for a fully-covered schema applies.

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?

States a specific verb+resource: fetches real bid/ask depth and slippage at three notional tiers from Binance and Bybit. It explicitly distinguishes itself from siblings by name (token_market_data, pre_trade_check) and scopes to CEX books only, so an agent can tell what it is without opening a schema.

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?

Provides explicit 'Use when' and 'Not for' clauses, naming the alternative tool (token_market_data for market cap/volume, pre_trade_check for a full pre-trade verdict) for each exclusion. The condition that selects this tool — estimating slippage before a large trade — is unambiguous.

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