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

Annotations already declare read-only/idempotent behavior, so the description adds valuable context beyond that: sale dates are 'the auctioneer's LOCAL calendar date' with no timezone, meaning a precise instant is unavailable at the sale level. This honest data-quality caveat helps the agent set expectations and route to the exact-time sibling when needed.

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?

Every sentence carries substance: concept definition, example, use cases, filters, return fields, and a necessary timezone caveat. The description is front-loaded and wastes no words while remaining readable.

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 tool with 7 parameters, no output schema, and many closely related siblings, the description is unusually complete: it covers scope, filters, return fields, and a critical date-precision caveat. It could more explicitly explain the relationship between closing-date filters and the returned 'local sale date', but the schema mitigates that by defining closes_after/closes_before.

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 100%, so all parameters are already documented with clear descriptions. The tool description only restates filter options (state, keyword, auction_house, closing date range) without adding new per-parameter semantics, landing exactly at the baseline for fully covered schemas.

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 a precise definition: 'Upcoming US auction EVENTS — the sales themselves rather than individual lots' and gives a concrete example. It also states the exact user questions it answers ('what auctions are happening near me next week' / 'what is this auction house selling'), making it clearly distinguishable from lot-level sibling tools.

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 explicit use cases, filter guidance, and an explicit contrast with individual lots ('rather than individual lots'). It also names the sibling tool us_auctions_closing_soon for exact lot close times, reinforcing when to use this tool vs. an alternative.

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