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

The readOnlyHint annotation already establishes this as a safe read, so the description's job is smaller; it still adds real behavior context by enumerating exactly which fields come back (name, interval, price in cents, for-sale flag, plan group). It does not mention ordering, pagination, or whether archived/legacy plans are included.

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 with no filler; the parenthetical field list is dense but every element is informative given the absence of an output schema. Slightly crowded but efficient.

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?

With no output schema and no parameters, the description carries the return-value burden and does so by naming the returned fields and the unit of price (cents). It stops short of covering pagination, ordering, or the GraphQL fallback route, which would seal the definition.

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 takes zero parameters, so there is nothing for the description to disambiguate. Baseline for a no-param tool is 4, and the description stays out of the way rather than inventing input semantics.

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?

States a specific verb and resource ('List all plans') and even maps the term to the Memberful dashboard label 'Prices', so an agent can distinguish it from list_passes and list_members. It does not explicitly contrast itself with sibling list tools, which keeps it from a 5.

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?

Usage is only implied: with no parameters, it is evidently the 'get everything' option, but the description never says when to prefer it over memberful_query or memberful_graphql for plan data. No exclusions or alternatives are named.

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