Get plan and billing status

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

Annotations already declare the safe read profile (readOnly, idempotent, non-destructive, closed-world), so the bar is lower. The description adds substantial context beyond that: the full return payload, the meaning of each plan/status value, and the important constraint that starting Pro, paying and cancelling must happen in the browser at billingUrl. It omits auth/rate-limit details, keeping it from a 5.

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 dense but front-loads the trigger condition before the return details, and nearly every sentence carries useful information (enum values, pricing, the browser-only mutation rule). It is somewhat run-on and could be tightened, but there is little pure filler.

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?

There is no output schema, so the description must describe returns, and it does so comprehensively down to individual fields and billingUrl. Combined with annotations covering the safety profile and a fully documented single parameter, an agent has everything needed to call this correctly.

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?

With one optional parameter at 100% schema coverage, the schema already documents workspaceId fully. The description adds only marginal meaning ('reads that workspace owner's plan'), which is essentially a restatement of the schema text, so the baseline 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 a specific verb and resource ('Returns the account's plan') and enumerates exactly what comes back (plan, Pro status, trial credits, usage, next charge, billingUrl). It is very clear on its own. The only gap is that it never distinguishes itself from the sibling billing_summary, so an agent must guess which of the two to pick.

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?

It gives explicit triggering conditions: 'Use this when a tool fails with PAYMENT_REQUIRED, or the user asks about their plan, trial or bill.' That is clear when-to-use context. It stops short of naming alternatives or exclusions (e.g. billing_summary), so it falls short of a 5.

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