Billing Summary

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

Annotations already establish that this is read-only (readOnlyHint=true, destructiveHint=false), so the description does not need to repeat that. The description adds useful scoping about which billing facts are returned, but it does not discuss behavior such as auth requirements, data freshness, or what happens when values are absent. With annotation coverage this is adequate but not rich.

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?

A single sentence that leads with the verb and immediately names the resource and return values. There is no filler, repetition, or irrelevant context, so every word earns its place.

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 summary tool with no required parameters, a rich output schema, and self-describing optional parameters, this description is nearly complete. The only notable gap is the absence of any explicit relationship to the closely named billing_* siblings, which an agent would have to infer from the return fields.

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 the parameters (baseUrl, profile, frontendUrl) are already fully documented in the schema. The description does not add any extra meaning about how these parameters affect the response, so the baseline score of 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 clear action verb ('Return') and names the exact resource ('Cloudeval billing') plus the specific data points: entitlement, credit status, and subscription status. It is clear about what the tool exposes, but it does not explicitly contrast with the related billing_* siblings, so it stops short of full differentiation.

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 listed return fields imply when this tool is appropriate—when an agent needs billing entitlement, credit, or subscription status. However, it gives no explicit guidance about when to choose billing_summary over billing_usage, billing_ledger, or billing_plans, leaving the routing decision mostly to inference.

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