prufa_billing_portal

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

With no annotations, the description fully carries the burden: it discloses the tool is mutating, idempotent, returns a URL for human action, and explains the error case (409 no_stripe_customer) with remediation steps.

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?

Three sentences, front-loaded with the main action and return value. Every sentence adds value: purpose, error handling, and behavioral traits. No extraneous content.

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 no output schema, the description explains the primary return (portal_url) and error handling. It is fairly complete, though additional detail about the response format would elevate it to 5. However, it is sufficient for an agent to understand and invoke the 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?

Schema coverage is 100% and already provides detailed descriptions for both parameters. The tool description adds no additional meaning beyond what is in the schema, so a 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 clearly states it opens the Stripe customer portal for the workspace, returning a URL for human management of subscription, card, or invoices. It distinguishes from siblings by mentioning prufa_upgrade_plan as a prerequisite when no customer exists.

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?

Explicitly describes when to use (manage subscription, card, invoices) and what to do on error (pass back 409 and redirect to prufa_upgrade_plan). Does not explicitly list when not to use, but the context is sufficient.

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