saas_api_update_rebilling

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

Annotations already indicate a write operation (readOnlyHint=false) and non-destructive behavior. The description adds the critical token requirement, which is useful. However, it doesn't describe side effects, reversibility, or what happens to existing rebilling settings when this is called, which would be valuable for an update operation.

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, and it front-loads the purpose before the token caveat. It is appropriately brief, though it could add a little more context without becoming verbose.

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 mutation with four parameters (including nested config) and no output schema, the description is under-specified. It omits the fact that it operates on multiple locations (though schema implies it) and doesn't explain what 'updating rebilling' affects (e.g., billing, tokens, product eligibility). An agent would need to inspect the schema and infer behavior, which is inadequate for a write operation.

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 schema already documents three of four parameters with descriptions (config, product, locationIds), and coverage is 75%. The description adds no parameter-specific information beyond the token requirement, which is not a schema parameter. Since the schema does the heavy lifting, a baseline 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 states the action ('Update Rebilling') with a clear verb and resource, and it is distinct from sibling tools like enable/disable or deprecated versions. However, it doesn't specify what 'Rebilling' entails beyond the name, relying on the schema for details like config fields and location scoping.

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 provides a prerequisite (agency-level token) but no guidance on when to use this tool versus alternatives such as enabling/disabling SaaS or other rebilling-related endpoints. There is no mention of scenarios or conditions that would select this tool, leaving the agent to infer from the name alone.

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