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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, open-world), and the description adds genuinely new behavioral context: bids flow through a 5-minute result cache and the current bid should be treated as a lower bound near close, never as the final price. That is an operationally important caveat an agent could not infer from annotations.

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-loaded with purpose and the returned fields, then provenance, then the cache caveat. Every sentence carries information; only the trailing 'Sourced from bigiron.com/Lots/{slug}' lightly restates the slug format already given.

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?

No output schema exists, and the description compensates by enumerating the returned fields and how active versus inactive lots differ (current bid / Buy-It-Now only for active lots). Combined with the staleness caveat and slug provenance, an agent has everything needed to call it correctly.

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 the baseline is 3, but the description adds meaning beyond the schema by explaining the provenance and shape of a slug (the segment after /Lots/ in a search result URL). It does not cover failure behavior for malformed or unknown slugs, which keeps it below a 5.

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 ('full detail for one bigiron.com lot') and enumerates the fields returned (description, sale status, bid count, make/model/year, seller, location, category, prices). It also implicitly distinguishes itself from the listing tools by naming bigiron_search and bigiron_sold_search as slug sources rather than detail sources.

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?

Explicitly tells the agent where the required slug comes from ('bigiron_search or bigiron_sold_search result urls, the part after /Lots/'), which is the key routing information. It stops short of an explicit when-not statement (e.g. use search tools when you don't yet have a slug), so it is clear context without stated exclusions.

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