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

Annotations already establish this as a read-only operation, so the bar is lower; the description still adds real behavior: results are sorted cheapest first, priced in USD per GPU-hour, and carry source page and read timestamp per quote, plus the 'live quotes only' constraint. It does not mention rate limits or cache/staleness windows beyond the live-only claim.

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 sentences, front-loaded with the resource and scope, then the ordering/unit and the freshness constraint. Every clause carries information; nothing is padded.

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?

With no output schema, the description does the work of describing returns: quote, source page, read time, ordering and unit. That is nearly sufficient, though it gives no detail on empty-result behavior or whether coverage across providers is exhaustive.

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 gpu, limit and market are already fully documented, including enum values and defaults. The description's 'cheapest first' and 'USD per GPU-hour' restate what the schema already conveys, so baseline 3 applies.

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 with scope: 'Current listed rental prices for one GPU model across providers'. The 'one GPU model across providers' framing implicitly separates it from siblings like provider_prices (one provider, many GPUs) and price_index, but 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?

Usage context is implied by 'current' and 'live quotes only', but there is no explicit when-to-use/when-not guidance and no named alternative among list_gpus, price_index, provider_prices or recent_price_changes. An agent must infer routing from scope alone.

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