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

Annotations already establish read-only, idempotent, non-destructive, closed-world behavior, so the bar is lower. The description adds meaningful scope: hundreds of expiries, recent settled expiries, side-by-side venue comparison, current upcoming max pain, and an explicit historical-not-predictive framing.

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 dense but front-loaded with the core data content, then follows with usage guidance. It avoids filler, though the first sentence is long and could be split for easier scanning.

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 an output schema present, the description need not describe return values. It adequately conveys the dataset scope and the historical-vs-predictive distinction; the main remaining gap is the semantics of the limit parameter.

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 50%: asset is described as the underlying asset with an enum, but limit has no description in the schema and is not mentioned in the description. The description does not explain what limit controls, despite implying recent expiries are returned.

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 identifies the resource: per-expiry max-pain settlement statistics, market-maker corridor hit rates, OI wall outcomes, recent settled expiries across Deribit/Bybit, and current upcoming max pain. It is specific and distinguishes itself from a prediction tool, but it does not differentiate from sibling tools such as market_state or hypothesis_ledger.

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?

It explicitly says to use this for questions like "will price pin to max pain on Friday?" and clarifies that it answers with historical hit rate rather than a prediction. That gives a clear usage context, though it does not name when to use alternatives or exclusions.

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