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

Annotations already declare readOnlyHint=true, destructiveHint=false, openWorldHint=false, so the safety profile is covered. The description goes beyond them with genuinely useful facts: each page costs one data unit, the 20/100 row defaults, and the 12-month UTC cap — quota cost in particular is not derivable from annotations or schema.

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 dense sentences, front-loaded with purpose, then pagination/cost, then cursor continuation; nothing is padding. The final sentence largely repeats the schema's own cursor instruction ('Reuse the same filters and limit'), a minor redundancy that keeps it off a 5.

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 4-parameter, nested-pagination tool with no output schema, the description covers purpose, units, history depth, page sizing and data-unit cost, which is enough to invoke correctly. It omits anything about data freshness/availability (covered by get_data_status) or what a row contains, leaving small gaps.

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, page.limit, page.cursor, count and months are all documented in the schema already, setting a baseline of 3. The description adds only marginal meaning — 'USD per whole node hour' hints at how count scales pricing — while otherwise restating the 20/100 limit and 12-month cap.

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 opens with a specific verb and resource ('Show how one GPU model's price changed month by month per provider') and pins down units ('on-demand and spot USD per whole node hour'). It separates itself implicitly from snapshot-style siblings by emphasising monthly history, but never names get_prices or get_market_snapshot, so the differentiation is inferred rather than stated.

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 only implied: 'month by month' tells the agent this is the trend/history call and the cursor note explains continuation, but there is no explicit when-to-use versus get_prices, get_market_snapshot or get_availability, and no prerequisites or exclusions. The agent must infer the routing from the noun 'history'.

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