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

The description opens with 'MUTATES Memberful data', directly signaling a write operation, which is consistent with the destructiveHint=true annotation. It adds context beyond the annotation by clarifying that only metadata is affected and by providing the underlying GraphQL mapping. It does not go into irreversible side effects, but the annotation already covers destructiveness.

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 sentences with no filler. The mutation flag is front-loaded, followed by the precise scope, constraints, and routing to an alternative. Every clause contributes 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 two-parameter tool with full schema descriptions and an annotation indicating destructiveness, this description covers the action, scope, constraints, and alternative path. No output schema exists, and the description does not need to explain return values for this simple metadata update. It is complete.

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 coverage is 100%, with both id and metadata documented in the schema. The description repeats the metadata constraints (max 50 keys, 40-char keys, 500-char values) but does not add new parameter meaning beyond the schema. It reinforces the scope, but that is more about usage than parameter 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?

The description states a specific verb and resource: 'update a member's metadata'. It also clearly scopes the action to metadata only, distinguishing it from the broader member update capabilities in sibling memberful_graphql. This precision makes it immediately identifiable.

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?

Explicitly instructs when to use this tool versus an alternative: 'Only metadata is supported here; for other inline member fields use memberful_graphql.' It even provides the exact GraphQL mutation name (memberUpdate) for reference, leaving no ambiguity.

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