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

Annotations already declare readOnly, idempotent, openWorld, and non-destructive, so the safety profile is covered. The description contributes real context beyond that: it identifies the source as a self-hosted official CFTC snapshot, mentions snapshot provenance and pagination in the return, and states the scope restriction. It stops short of detail on how the snapshot is refreshed or how provenance is exposed.

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, front-loaded with the verb and scope, then the return inventory, then usage examples and the boundary clause. The return list is long but each item is informative, so little is wasted.

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?

No output schema exists, so the description must describe returns, and it does so thoroughly (codes, names, commodity/exchange labels, report families, scopes, latest date, pagination, provenance). Combined with a fully documented 6-param schema and complete annotations, an agent has everything needed to call 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%, including enum values and defaults, so the schema carries the parameter burden and the baseline is 3. The description adds only thematic context ('available report families and scopes'), not syntax or format guidance beyond what is already documented.

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?

States a specific verb (search) and resource (CFTC contract markets) bounded to a self-hosted official COT snapshot, and enumerates exactly what is returned (codes, names, labels, report families, scopes, latest date). It also carves out the boundary ('aggregate US futures and options markets only; not quotes or prices'), separating it from price/quote siblings.

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?

Gives concrete when-to-use examples ('find the CFTC code for gold', 'which COT markets cover crude oil?') and names the workflow position ('resolve an identifier before a history call'), routing the agent toward cftc_cot_history. The 'not quotes or prices' clause functions as an explicit when-not.

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