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

The description adds that the records are 'GCP Billing BigQuery export credential records' and scoped to the install, complementing the readOnlyHint=true annotation. It does not contradict any annotations.

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?

Single, efficient sentence with no filler, perfectly sized for the information conveyed.

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 simple read-only list with one optional parameter and no output schema, the description covers the essential scope. Could mention return format but not required for this type of tool.

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?

The description and schema provide no information about the 'account' parameter (0% schema coverage) and the description doesn't mention parameters, leaving the agent without guidance on filtering or expected format.

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 the specific verb 'List' with the resource 'GCP Billing BigQuery export credential records linked to this install,' clearly distinguishing it from siblings like gcp_billing_cost or gcp_billing_top_services.

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?

Provides context that the tool is scoped to the current install but does not explain when to prefer it over alternatives or when not to use it. The usage is implied but not explicit.

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