Show the paid plan

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

Annotations already carry readOnlyHint=true, and the description reinforces this while adding a meaningful external guarantee: 'Never contacts Stripe.' It also discloses that it surfaces pending upgrade offers, which adds useful behavioral context beyond the structured 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 two sentences, front-loads the core purpose, and includes only high-value details: pricing model, status fields, read-only behavior, and Stripe non-contact. There is no filler or repetition.

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 zero-parameter read-only tool with no output schema, the description adequately covers what the caller should expect to receive: plan type, pricing details, status, period end, and pending upgrade offers. Nothing essential is missing for correct invocation.

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 tool has zero parameters and an empty input schema, so there is no parameter burden for the description to carry. Per calibration, this earns the baseline score of 4.

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, 'Show the account's plan', and enumerates exactly what will be shown: free tier or paid blocks, status, period end, and upgrade offers. It also distinguishes itself from mutation siblings like upgrade by stating it never changes anything and never contacts Stripe.

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 usage context is inferable: this is the read-only tool for inspecting the account's plan and pending upgrade offers. However, it does not explicitly name alternatives like upgrade, trial, or usage, nor does it state when not to use this tool.

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