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

Annotations already cover safety (readOnly, idempotent, non-destructive, closed-world), so the bar is lower. The description adds real behavioral context beyond them: results are ranked by ascending median price, values are current ('agora'), and top_n is bounded at 10. It does not describe pagination or data freshness beyond the word 'now'.

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 short sentences with the resource and ranking stated first, and the parameter bounds tucked into a parenthetical. Nothing is padded, though the parenthetical slightly interrupts the flow.

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 tool with no output schema, the description covers the ordering and the top_n bounds but never says what a result row contains (state plus price?). That return-shape gap keeps it at a minimum-viable level rather than 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 description coverage is 0%, so the description must compensate. It documents top_n's default (5) and maximum (10), which the schema's bare title does not, but car_id is left uninterpreted beyond its name, so only part of the parameter semantics is recovered.

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 states a specific verb+resource: returns the states (UF) where a given model is currently cheapest, ordered by ascending median price. That is concrete enough to distinguish it from siblings like get_price_distribution or get_market_position, though no sibling is named explicitly.

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?

It gives a trigger scenario ('Use for where is cheapest to buy'), which is clear implied usage, but it names no alternatives and no conditions for when NOT to use it versus e.g. get_price_distribution or get_market_stats.

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