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

The description goes beyond the readOnlyHint annotation by explicitly stating 'READ-ONLY. Does not place orders, move funds, or mutate your exchange account.' It also discloses caching (~1800s), auth requirements, cost, rate limit, and the billing nature—all critical behavioral traits not present in annotations. No contradiction with 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?

The description is well-structured with labeled sections (Purpose, Behavior, Auth, Cost, Returns, Guidelines) and front-loaded with the core functionality. However, it is slightly redundant—'Detects and tracks CME Bitcoin futures gaps' appears both in the opening sentence and the Purpose section, and the 'Unique signal' phrase is repeated. Still mostly efficient.

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?

Given the tool's complexity, the description covers all essential context: return format (array of gaps with direction, size, fill status, dates), auth mechanism, cost, rate limits, caching, and appropriate use cases. The output schema also exists, so the description does not need to over-explain return values. No critical gaps.

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 100% for the single optional parameter __x_payment, including its purpose and usage. The description adds only a brief mention of the parameter in the auth section, which restates rather than expands on the schema. Baseline 3 is appropriate since the schema carries the full load.

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 'Detects and tracks CME Bitcoin futures gaps (Friday close vs Monday open) with fill status monitoring.' This is a specific verb+resource statement that distinguishes it from sibling tools which focus on other market data. The 'Unique signal' tag reinforces its distinctiveness.

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 provides explicit usage guidance: 'Use for research / signal context. Pair with cc.agent_strategy (paper) before any live order. Do not invent fills from this data alone.' This tells the agent when to use the tool and pairs it with an alternative/complement, exceeding basic clarity.

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