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

Annotations already signal destructiveHin=true, and the description adds 'MUTATES' plus the underlying GraphQL mutation name. However, it does not disclose side effects, authorization requirements, duplicate handling, or what happens on successful creation, so extra behavioral context is limited.

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?

Two concise sentences with no filler. The mutation warning is front-loaded, and the second sentence gives implementation-specific context that helps an agent understand the backend call without clutter.

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 simple 2-parameter mutation with no output schema, the description provides enough to invoke the tool correctly: it names the operation, the resource, the required email, and the optional fullName. It could briefly mention expected return behavior or duplicate handling, but those are not essential for 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?

Schema description coverage is 100%, so the schema already documents email and fullName. The description adds only the GraphQL argument mapping (memberCreate(email, fullName)), which is useful but does not substantially deepen parameter meaning beyond the schema.

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 uses a specific verb, 'create', and identifies the resource, 'a new member', while also noting the mutation nature and the required/optional fields. This clearly distinguishes create_member from sibling tools like update_member, get_member, and list_members.

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 implied rather than explicit: the agent can infer this tool is for creating new members, but the description does not state when to use it over alternatives such as update_member or memberful_graphql, nor does it mention exclusions.

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