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

Annotations already declare readOnlyHint=true, and the description adds useful behavioral context beyond that: it specifies that all plans are returned, lists the exact response fields, and identifies the underlying data source as Memberful GraphQL 'plans'. It does not mention pagination or ordering, but for a simple read-only list this is a minor gap.

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?

A single, front-loaded sentence states the action first, then the returned fields and source, with no wasted words. Every clause adds useful information.

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 list tool with no output schema, the description is sufficiently complete: it names the resource, lists the returned data, and identifies the GraphQL source. It could add explicit sibling differentiation or pagination behavior, but these are not critical for invoking this simple tool 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?

The tool has zero parameters and schema description coverage is 100%, so there are no parameter semantics for the description to clarify. The description focuses on what is returned rather than input details, which is appropriate here.

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 ('List'), a clear resource ('all plans'), and enumerates the return fields (name, interval, price in cents, for-sale flag, plan group), making it easy to distinguish from sibling list tools such as list_members, list_subscriptions, and list_passes. It also anchors the concept to Memberful's dashboard terminology ('Prices').

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 intended use—retrieving all pricing plans—is clearly implied, but the description does not explicitly state when to choose this tool over alternatives or provide exclusions. Sibling names make the choice fairly obvious, yet no direct 'use this instead of X' guidance is given.

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