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

Beyond the readOnly/idempotent/non-destructive annotations, the description discloses the method ('Pulls the full public L2 book and walks it'), output units ('slippage is vs. mid price, in basis points'), null semantics for thin books, and cost per call. This is substantial behavioral context with no contradiction to 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?

Four focused sentences, front-loaded with the core question ('How much size a market can take'), followed by output details, use cases, and pricing. Every sentence adds useful information without repetition or fluff.

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?

The description covers output metrics, units, error/null behavior, venues, use cases, and cost, which is strong for a read-only tool with no output schema. It is incomplete mainly on pair-format convention and the units of the spread field, both of which an agent would need to fully trust the output.

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 names the venues, which loosely matches the enum, but it never explains the required pair parameter's expected format (e.g., 'BTC-USD' vs 'BTCUSD'). Since pair is the only required parameter, this is a significant gap for an agent trying to call the tool correctly.

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 what the tool computes: bid/ask depth at multiple percentages, spread, and slippage for market orders on three named venues. It uses a concrete resource ('full public L2 book') and explains the output in terms of market impact, making it easy to distinguish from price/ticker 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 gives explicit use cases: 'Use before sizing an order or comparing venue liquidity.' This is clear context, but it does not spell out when not to use the tool or name an alternative for simple price checks, so it stops short of a full routing guide.

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