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

With no annotations, the description carries full disclosure burden. It reveals the $0.03 USDC cost, states it 'Rejects stale books,' and clarifies it does not place orders. It does not mention rate limits or auth, but the read-only nature and fee are clearly disclosed.

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 two sentences with no filler. It front-loads the cost and core operation, then lists exclusions efficiently. Every clause adds useful information.

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 paid, 6-parameter tool with an output schema and no annotations, the description covers purpose, cost, stale-book handling, and safety. It omits some parameter semantics and alternative routing, but the schema supplies defaults/enums and the output schema covers return values, making it nearly complete.

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 compensate. It explains trade_size_usd ('requested trade size'), fee_bps_by_venue ('caller- or server-configured taker fee assumptions'), and venues ('Binance and Coinbase'). However, quote_asset and min_net_spread_bps are left undocumented, though their names/defaults make them partially inferable.

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 states a specific verb and resource: it 'Compares Binance and Coinbase public spot order books at a requested trade size and applies... taker fee assumptions.' It also differentiates from siblings by explicitly saying it 'does not place orders' and excludes guaranteed execution, so an agent can distinguish it from execution or quote tools.

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 implies usage for arbitrage scanning and gives negative boundaries ('Excludes transfers, inventory rebalancing, and guaranteed execution; does not place orders'), but it never names sibling alternatives like get_live_quote or estimate_trade_execution, nor states explicit when-to-use versus when-not-to-use conditions.

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