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

The description adds real behavioral value by disclosing the improvement threshold ('beats the earlier best by at least $100 a year or 5%'), which no structured field provides. However, annotations declare readOnlyHint=false while the description frames the operation purely as a passive 'check', leaving unexplained whether the call re-queries carriers or mutates the quote session. With annotations present the bar is lower, but this gap is notable.

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?

Four sentences, front-loaded with the core purpose followed by usage and result-handling guidance; every sentence carries information. Slightly longer than strictly needed, but nothing is filler.

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?

An output schema exists, and the description still explains the key field's semantics (has_improvement and its threshold), which goes beyond requirement. Combined with clear usage and reporting guidance, the definition is near-complete; the only missing piece is any note on why the tool is flagged as non-read-only.

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% and the single quote_id parameter is fully documented in the schema, so baseline 3 applies. The description's phrase 'since the options were first shown' loosely reinforces that quote_id scopes to an existing options session, but adds no format or constraint detail beyond the 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?

States a specific verb and resource ('checks whether a slower carrier has come back with a better price') plus the triggering condition ('since the options were first shown'), which separates it cleanly from siblings like get_quote_options and check_quote_status. An agent can route to it 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?

Gives a clear situational trigger ('useful when the customer hesitates over price after seeing options') and explicit guidance for the negative case ('say so plainly rather than suggest a better price is coming'). It stops short of naming a concrete alternative tool, so it is strong context rather than full when/when-not routing.

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