Spread and liquidity over time

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

With no annotations, the description carries the full burden. It discloses that the metrics are derived, cheaper than order-book retrieval, and that spread validity is conditional on both order book sides being populated. The settlement caveat adds beyond the title, but it does not mention pagination behavior or response format beyond 'time series', still leaving a minor gap.

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?

Two concise sentences: first presents what it does, second adds the use-case distinction and an important caveat. No filler or redundant restatement of the name.

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?

Despite six parameters and no output schema, the description clearly conveys the expected output type (time series of metrics) and the main usage condition. Given the schema supplies high parameter coverage, the only missing part is pagination/cursor semantics, which the schema's 'cursor' field already hints at. Overall adequate, but not exhaustive.

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 83%, so the schema already documents most parameters well. The description adds meaningful context about what the returned metrics refer to (spread, liquidity, volume), but does not explain specific parameter details like cursor or limit beyond what schema says.

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?

Clearly states the verb and object: it gets derived market quality metrics (spread, liquidity, volume) as a time series. It also distinguishes itself from the order-book sibling by saying it is cheaper than pulling full order books, making its scope unambiguous.

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?

Explicitly tells when to use: 'when the question is about market quality rather than specific price levels' and contrasts with the costlier 'full order books' alternative. It also provides a specific caution about spread near settlement, which acts as a when-not-to-trust boundary.

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