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

No annotations exist, so the description carries full responsibility. It thoroughly discloses behavioral nuances: the distinction between standard and DST values, the existence of `season_now` and `operative_cutoff_today`, the warning to quote today's operative cutoff rather than defaulting to winter values, and the alias handling for T2/TARGET2. This goes far beyond a basic read-only query description.

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?

Despite being long, the description is well-structured with clear sections (coverage, guidance, DST warning, Args, examples). Every sentence carries meaningful information—there is no fluff. The prominent DST warning is placed close to the top, ensuring agents notice the critical pitfall.

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?

Given the tool's complexity (many systems, DST handling, multiple parameters) and the presence of an output schema, the description is remarkably complete. It covers system coverage, currency filtering logic, DST behavior, parameter semantics, and usage examples. The guidance about which cutoff to quote is especially valuable for correct real-world usage.

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?

The input schema provides only types without descriptions, so the description compensates fully. It explains both parameters in an 'Args' section, giving concrete examples ('system="T2"', 'currency="EUR"'), notes case-insensitivity, and clarifies that 'TARGET2' and 'T2' resolve to the same entry. This adds substantial meaning beyond the schema structure.

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 'Get payment system cutoff times for major clearing systems', a specific verb-resource pairing. It further details the exact systems covered (RTGS, net settlement, SEPA, FX, etc.) and distinguishes itself from sibling tools by focusing solely on cutoff times, not other payment-related queries.

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?

Provides clear usage guidance, e.g., 'For same-day EUR guidance: filter by currency="EUR" to retrieve all SEPA schemes plus T2 in one call' and explains how to interpret DST-sensitive values. While it does not explicitly mention when not to use or name alternatives (like settlement_eta or value_date), the instructions are concrete and contextual enough for an agent to apply correctly.

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