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

Annotations already cover read-only, idempotent, non-destructive behavior, so the bar is lower. The description adds genuinely new context by noting the data is keyless and officially sourced from the Treasury, which tells the agent no credentials or setup are needed and the source is authoritative.

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 tight sentences with zero filler. The core identity and returned shape are front-loaded before the supporting provenance note.

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 three-parameter read-only tool with no output schema, the description usefully describes what comes back (recent figure plus history, with the two debt components split out). It does not clarify default behavior when no date range is supplied, but that is a minor gap.

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%, so limit, start_date, and end_date are fully documented in the schema itself. The description adds no format, default, or interaction detail (e.g., what happens if no dates are given), so it sits at the baseline for a fully-covered schema.

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?

Names the specific series ('Debt to the Penny'), the issuing body, and the exact content returned (most recent figure plus history, split into public debt and intragovernmental holdings). An agent can distinguish this from treasury_auctions, treasury_cash_balance, or treasury_interest_rates without opening the schema.

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 the tool's use (US total debt data, recent plus historical), but offers no explicit when-to-use framing, no mention of date-range scoping intent, and no pointer to alternative treasury tools for related questions. Usage is inferable rather than stated.

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