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

Beyond readOnly/openWorld/idempotent/non-destructive annotations, the description adds useful behavioral context: it surfaces open interest and the largest absolute reported category net per view, preserves incompatible family classifications, and is explicitly not real-time or trading advice. This goes beyond what annotations alone convey.

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?

Three sentences, no filler: the first states the core function, the second summarizes output semantics, and the third gives usage examples and caveats. The content is front-loaded and every sentence earns its place.

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?

For a complex aggregation tool with no output schema, the description covers what the pack contains, what metrics are surfaced, and how incompatible classifications are handled. It does not detail the exact response structure, but combined with the schema and annotations it is sufficient for correct invocation.

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 baseline is 3. The description's 'one contract market' phrasing aligns with the existing market parameter but does not add substantive meaning beyond the schema, and the response_format parameter is already fully documented by 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 names a specific verb ('Combine') and resource (all hosted CFTC COT report-family and scope views for one contract market) and states the output (a provenance-backed evidence pack). It clearly distinguishes itself from the sibling single-view tools like cftc_cot_latest and cftc_cot_history by emphasizing aggregation of all views.

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-case examples ('build a COT evidence pack for gold', 'show every CFTC positioning lens for crude oil') and frames the tool as research synthesis, not real-time data or trading advice. It does not explicitly name alternatives or state when not to use it, but the context is clear.

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