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

Annotations already establish read-only, idempotent, closed-world behavior, and the description goes beyond them by disclosing the data source (latest Legacy report), the market coverage (35 markets across six asset classes), what is measured (speculator/commercial net positions plus change), and the authentication tiers that gate variant selection. It does not describe result ordering, units, or how a 'weekly' period is bounded.

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 resource and coverage, with no filler. The middle sentence 'Available at every level' is vague enough that it does not clearly earn its place and interrupts the otherwise logical content-then-access flow.

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 one optional enum parameter, no nested objects, no output schema, and full annotation coverage, the description supplies what an agent needs: what data comes back, which report it derives from, market scope, and account-level constraints on the variant. The remaining gaps — return value shape, units, and which week is returned — are modest for a read-only summary tool.

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 coverage is 100% and the single enum parameter is fully documented with defaults, so the schema already carries the load. The description adds a genuinely useful entitlement constraint — paying keys get both CFTC variants while unauthenticated/free users are locked to each report's default variant — but it does not elaborate on how variant choice affects the returned numbers.

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 concrete verb and resource: it returns the weekly summary of net speculative/commercial positions for 35 named market groups from the latest Legacy report, and specifies that change data is included. That is far more specific than the title alone and implies a weekly-snapshot scope distinct from the point-in-time siblings get_latest_positions and get_latest_snapshot, though it never names those siblings explicitly.

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?

Usage is only implied: 'The weekly summary ... from the latest Legacy report' suggests this is the periodic overview rather than an ad-hoc query, and 'Available at every level' gestures at coverage of market hierarchy levels. There is no explicit statement of when to pick this over get_latest_positions, get_history, or get_cot_index, leaving the agent to infer the choice.

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