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

Annotations already mark this read-only, idempotent and non-destructive, so the safety profile is covered. The description adds genuinely useful behavior context beyond them: the distinction that on_demand instances can't be interrupted while spot machines can be reclaimed, which materially affects the agent's choice.

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?

Three short sentences, front-loaded with what the tool returns before covering pricing_type and limit. Nothing is redundant and every sentence carries new information.

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 an output schema present and rich annotations, the description needn't explain return values, and it is complete enough to call correctly for all three parameters. Minor gaps remain around invalid family names and default limit behavior, but these are not blocking.

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 carry all parameter meaning and largely does: it gives family-name examples for 'gpu', defines both values of 'pricing_type' with the default, and states the 1-10 bounds for 'limit'. It omits only the default value of limit (5) and the exact accepted string format for gpu.

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 resource ('cheapest current rental offers'), scope ('one GPU family'), unit ('USD per GPU-hour'), ordering ('cheapest first') and output grain ('one row per provider'), with concrete examples of family names like 'H100' and 'b200'. The word 'current' implicitly separates it from siblings gpu_price_history and gpu_price_forecast.

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 is implied by the word 'current' and the per-family scoping, so an agent can infer this is the live-price lookup rather than the historical or forecast tools. However, no sibling is named and there is no explicit statement of when to prefer it over gpu_price_history or cheapest_model_route.

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