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

Annotations already declare readOnly/openWorld/destructive, so the safety profile is covered. The description adds meaningful behavior beyond that: a two-stage lifecycle where results fields are null until post-auction, idempotent saves keyed on cusip + auction_date, and the TIPS/FRN flag-resolution quirk.

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?

Front-loads the core purpose and organizes the rest into scannable bullet groups. It is on the longer side and the signal-field list could be trimmed, but each section carries distinct information rather than restating the schema.

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 10-parameter read tool with no output schema, the description does the heavy lifting: it explains the record shape, key return fields, lifecycle states, and filter quirks. Only the absence of explicit sibling routing keeps it from being fully complete.

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 the baseline is 3, but the description adds genuine meaning on top: it explains that security_type:'TIPS'/'FRN' resolve to inflation-indexed/floating-rate flags rather than native types, and gives interpretation thresholds for bid_to_cover_ratio.

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 verb and resource ('Returns Treasury security auctions') and enumerates the covered instrument classes (Bills, Notes, Bonds, TIPS, FRNs). It does not explicitly name or contrast against a sibling, so it falls just short of the top band.

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?

Offers practical guidance on filtering ('Use security_type filter to focus on one term group') and interprets signal fields, but never states when to choose this tool over alternatives or any exclusion conditions. Usage context is implied rather than explicit.

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