Analyse Billing Costs

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

There are no annotations, so the description carries the full burden of behavioral disclosure. It only says 'perform detailed cost analysis with trends and insights,' which implies a read-only operation but does not explicitly confirm non-mutating behavior, describe the response shape, mention access requirements, or note any limits or error conditions. The schema covers inputs, but the behavioral context is largely missing.

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 a single concise sentence with no filler, front-loading the core action and resource. Every word earns its place, and it is appropriately sized for a short tool description.

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 annotations, no output schema, six parameters, and numerous closely related billing siblings, this description is not complete enough. It does not clarify the output format (e.g., cost breakdown, trend series), explicitly state that the tool is read-only, or explain how it relates to gcp-billing-service-breakdown and gcp-billing-detect-anomalies. An agent could call it, but would lack sufficient context to predict results or confidently choose it among alternatives.

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 each parameter is already documented with formats (ISO dates), enum options (groupBy), and filter semantics (projectId, serviceId). The description itself adds no parameter-specific meaning beyond framing the activity as analysis, so it neither compensates nor detracts. A baseline 3 is appropriate.

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 uses a specific verb ('perform') and resource ('Google Cloud billing data') and states the task ('detailed cost analysis with trends and insights'). It is distinguishable from sibling billing tools like list accounts or list services because it promises analysis rather than listing. However, it does not explicitly differentiate itself from closely related cost-analysis siblings such as gcp-billing-service-breakdown or gcp-billing-detect-anomalies, leaving some scope ambiguity.

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 description gives no explicit guidance on when to use this tool versus its many billing siblings. It does not say that this is the general cost-analysis tool while detect-anomalies, cost-recommendations, or service-breakdown cover specialized sub-tasks, nor does it mention prerequisites beyond the required parameters. Usage is only implied by the name.

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