Get cost summary

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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is known. The description adds no extra behavioral context (e.g., time range defaults, granularity handling, or response shape). It doesn't contradict annotations, so a baseline 3 is appropriate.

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?

The description is extremely concise: one declarative sentence plus two illustrative examples. No wasted words, and the main functionality is front-loaded.

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 and 6 optional parameters, the description should explain return values and parameter semantics more thoroughly. It covers basic summarization but omits important details like filtering by provider, category, and date ranges, as well as default granularity behavior. This is a moderate-complexity tool left under-specified.

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% and there are 6 parameters, but the description only hints at groupings like service/account/region without mapping to actual parameter names (provider, account, category). The examples imply date-range usage but don't clarify date formats, granularity options, or null semantics. This is insufficient compensation for zero schema coverage.

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 clearly states the tool's function: 'Get total spend summarized by service, account, and region.' This is a specific verb and resource with scope. It doesn't explicitly differentiate from siblings like estimate_change_cost, but the purpose is unambiguous.

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?

The examples ('How much did we spend last month?' and 'Give me an AWS cost summary for January') provide clear contextual usage for cost summary queries. There is no explicit exclusion or alternative comparison, which prevents a 5.

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