create_customer_portal_session

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

Annotations indicate readOnlyHint=false and destructiveHint=false, but the description adds valuable behavioral context beyond this: it explains that the tool returns authenticated links that automatically sign in the customer, specifies that sessions are temporary and shouldn't be cached, and details what happens for paused/canceled subscriptions. This enhances understanding of the tool's behavior without contradicting 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?

The description is well-structured with clear sections: purpose, portal capabilities, usage warnings, authorization notes, URL details, and behavioral notes. While comprehensive, some sentences could be more concise (e.g., the list of portal capabilities is lengthy but informative). Overall, it's front-loaded with key information and avoids redundancy.

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?

Given the tool's complexity (creating authenticated sessions with security implications), the description provides substantial context: it covers purpose, usage guidelines, behavioral traits, and output details (URLs and session entity). However, without an output schema, it doesn't fully document the response structure (e.g., exact fields in the 'new customer portal session entity'). This minor gap prevents a perfect score.

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%, with clear documentation for both parameters (customerId and subscriptionIds). The description adds some semantic context by explaining that subscriptionIds create 'authenticated customer portal deep links' and affect the returned URLs, but this is marginal beyond what the schema already provides. The baseline score of 3 is appropriate given the high 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 specific action ('create a customer portal session') and resource ('for a customer in Paddle'), distinguishing it from sibling tools like 'create_customer' or 'create_client_side_token' which perform different operations. It provides concrete examples of what the portal enables, making the purpose 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 description explicitly states when to use this tool ('Don't use this tool without checking with the user first. Avoid using before gaining explicit approval') and provides prerequisites ('Ensure those creating a customer portal session are authorized to access the customer portal'). It also implies alternatives by specifying what the portal does, helping differentiate from direct API calls for individual actions like managing subscriptions.

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