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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and a closed world, so the safety profile is covered. The description adds genuinely new behavioral context: the dataset size (350+ markets) and the exact shape of each returned record, which annotations cannot convey and which matters since there is no output schema. It omits any note on result volume or pagination beyond the schema's limit field.

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 compact sentences with the resource and return fields front-loaded, followed by the filtering options. The trailing phrase 'Available at every level' is vague filler that costs a sentence slot without conveying a concrete constraint.

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 no output schema, the description usefully enumerates the fields returned per market, and it covers all three filter dimensions plus dataset scale. The one meaningful gap is pagination/result-volume behavior, which the schema only partially addresses via limit; the cryptic availability sentence does not fill it.

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 all four parameters are already documented, including the report enum and example categories. The description only restates the filter axes (search text, category, report family) without adding syntax, matching behavior, or defaults, and it never mentions the limit parameter. Baseline 3 is appropriate when the schema carries the parameter burden.

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 opens with a specific verb and resource ('Lists the CFTC markets COT-Reports covers') and enumerates the returned fields (CFTC code, ticker, name, exchange, category, report families), which makes the tool's job unambiguous. It does not explicitly differentiate itself from the closest sibling, get_cot_index, so it stops short of a 5.

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 filtering options imply the lookup/discovery use case (finding a market's code or ticker before calling other tools), but that workflow is never stated. There is no explicit when-to-use or when-not-to-use guidance and no named alternative. 'Available at every level' is too cryptic to function as usage guidance.

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