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

The annotations already include readOnlyHint=true, and the description reinforces this by saying mutations are rejected and naming the correct alternative for write operations. It adds useful behavioral context beyond the annotation: arbitrary queries are allowed, mutations fail, and the endpoint is explicitly identified.

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?

Three dense sentences: the first identifies purpose and endpoint, the second states the exclusion and alternatives, and the third gives a concrete use case. There is no filler or redundancy beyond the intentional emphasis on read-only behavior.

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 only two parameters, no output schema, and a read-only annotation, the description covers everything an agent needs to decide and invoke correctly: endpoint, allowed operation, rejected operation, alternative tools, and a motivating use case. The arbitrary return shape cannot be described meaningfully in advance.

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 query and variables already described in the input schema. The description repeats that variables are optional but does not add deeper parameter semantics. Baseline 3 is appropriate because the schema carries the parameter documentation burden.

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 ('run'), a precise resource (arbitrary Memberful GraphQL queries against /api/graphql), and a clear scope (read-only). It also distinguishes itself from the curated read tools by framing it as an escape hatch for uncovered fields, which prevents confusion with siblings.

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?

It explicitly says to use this tool when fields are not covered by the curated read tools, gives a concrete example (member-state filters beyond active), and clearly tells the agent to use dedicated write tools or memberful_graphql for mutations. This is strong when-to-use and when-not-to-use guidance.

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