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

Beyond the annotations, which already declare read-only, idempotent, non-destructive behavior, the description adds substantial operational context: newest-first ordering, a 260-report cap, paging semantics, account-tier data availability, Premium close prices, and trial-subscription behavior.

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 core purpose is front-loaded and most of the dense access-tier material is substantive. The description is still a long multi-clause paragraph with some repetition, such as repeated 'without an account' phrasing, which slightly reduces clarity.

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?

There is no output schema, but the description identifies the returned content and explains paging, access tiers, report families, and variants for a relatively complex tool. This is enough context for an agent to select and invoke it correctly.

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 100%, so the schema already explains the parameters well. The description still adds meaning by clarifying 'until' for paging back, the 260-report limit, report-family availability by access tier, and default variant behavior, though it adds little about 'from' beyond the schema.

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 states a specific verb and resource: 'Weekly COT history for one market, newest first.' It also identifies the returned content (open interest and net positions by trader group), making it distinguishable from siblings like get_latest_positions and get_weekly_summary.

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 gives clear context for when this tool is appropriate by emphasizing history and explaining that callers can page back with 'until.' However, it does not explicitly name alternative sibling tools or contrast their use cases, so it falls short of full when-not/alternatives guidance.

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