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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint and destructiveHint=false, so the safety profile is covered. The description adds genuinely useful context beyond annotations: the data provenance (public-domain Fiscal Data) and a per-call cost ($0.003/call) that lets an agent budget. It does not, however, disclose the default time window or the shape of the response.

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?

Two sentences, front-loaded with the resource and returned fields, then routing guidance. The cost note is compact and earns its place for an agent tracking spend. Slightly dense with parenthetical field lists but no wasted sentences.

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 two-parameter, no-output-schema tool, the description covers what data comes back at a field level and where it routes, which is the minimum viable. It still leaves the optional 'days' semantics, defaults, and the overall response structure undocumented, so an agent cannot confidently predict the window of results it will receive.

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 0%, so the description carries the full burden, and it largely fails. 'days' is never explained (lookback window? forward calendar horizon? default value when omitted?), and the 'type' enum (Bill/Note/Bond/TIPS/FRN/CMB) is left to the raw schema tokens. The mention of 'size' does not map to any actual parameter.

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 resource (U.S. Treasury auctions) and enumerates the concrete fields returned — high yield, bid-to-cover, indirect/direct/primary-dealer share — plus the upcoming calendar. It also explicitly differentiates itself from the sibling 'calendar' tool, so an agent can distinguish the two without opening either 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?

Gives a direct when-to-use ('Use for U.S. Treasury auction results and the upcoming calendar') and names the alternative with its own routing condition ('for all macro releases use calendar'). The boundary between this tool and the sibling is stated, not inferred.

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