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

Annotations already declare readOnlyHint and openWorldHint, but the description adds valuable behavioral context beyond these: it is 'Experimental (may change or be withdrawn),' it 'costs $0.05 per call,' and it discloses 'the disclosed record only, no forecast.' These details warn the agent about volatility and cost, which are not captured in annotations. No contradiction with annotations; it complements them.

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 moderately long and front-loads an 'Experimental' parenthetical that, while important, adds verbosity before the core purpose. The structure is clear (purpose, matching, cost) but could be tightened by moving the experimental note to a single clause. Every sentence has a purpose, but the opening is heavier than necessary.

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 read-only data retrieval tool with no output schema, the description thoroughly explains what is returned (longs, shorts, net, share of open interest, changes), the matching rule, limitations (no forecast, disclosed record only), and the cost. It also flags experimental status. The agent has enough to call it correctly without missing critical expectations, though pagination or response format are not detailed—minor given the tool's simplicity.

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% for both parameters; the schema already explains 'weeks' with max/default and 'market' as a contract name fragment with examples. The description reiterates the matching-by-fragment behavior and gives the same examples, adding no novel semantic information. Since the schema handles parameter meaning well, a baseline score of 3 is appropriate; the description does not compensate for any gaps because none exist.

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 explicitly states the tool provides Weekly Commitments of Traders positioning, listing the exact metrics (non-commercial/commercial longs, shorts, net, share of open interest, week-over-week changes). It clarifies matching by contract name fragment, which distinguishes it from sibling tools like crop_data or energy_data that cover other data domains. The verb 'provides' and resource ('CFTC futures positioning') are specific and unambiguous.

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 implies when to use it (when CFTC futures positioning data is needed) and even gives matching examples, but it does not explicitly mention alternatives or exclusions. It only notes it is 'outside the core SEC path,' which hints at scope but does not name sibling tools or state when not to use it. For an agent, the domain is clear, but guidance on selection among siblings is absent.

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