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

Annotations already declare readOnly, idempotent and non-destructive, so safety is covered. The description adds genuine value on the read side: what is returned (timestamp, spread, largest displayed levels, bounded depth coverage) and what is out of scope (hidden stops, guaranteed support). No cost, rate-limit or auth context, which keeps it at 4 rather than 5.

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?

Three short sentences, front-loaded with the verb and scope, then routing, then return shape. Every clause carries information and nothing is repeated.

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 return values itself and does so adequately (timestamp, spread, largest levels, depth bound). Exclusions preempt the most common misreading of order book data as support/resistance. The only gap is the spot-vs-perpetuals wording, which is minor against an otherwise complete picture.

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 80%, so the schema largely documents levels, market, symbol, exchange and the notionalQuote VWAP caveat, giving a baseline of 3. The description's 'largest displayed levels' and 'bounded depth coverage' loosely frame the levels parameter but add no syntax or format detail. Minor inconsistency: the description says 'perpetuals' while the market enum also permits 'spot'.

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 and resource ('Read current displayed resting bid/ask limit orders') and scopes it to four named venues. It explicitly distinguishes itself from the sibling orderflow_read, so an agent can route correctly without opening either 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?

Gives positive triggers ('resting liquidity, order book/DOM and buy/sell walls'), a named alternative with the condition that selects it ('NOT orderflow_read, which reads executed trades'), and exclusions ('Not historical depth, hidden stops or guaranteed support'). Nothing is left to inference.

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