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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds useful non-schema context on authentication ('Needs the user's Cotlet API key with access to this app') and clarifies the semantics of the member count value.

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?

Mostly front-loaded and readable, but 'Skool: Skool groups you belong to' redundantly restates the title, and 'Member count is the number Skool shows on the group page' is low-value filler. A tighter version would drop those without losing 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?

With no output schema, the description carries the burden of describing returns and does so (role, member count, the group identifier). It also covers the auth requirement. It stops short of discussing pagination or ordering, which is the only meaningful gap.

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 the baseline is 4. There is no input to document, and the description correctly focuses on output shape (role, member count, group field) 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 (list) and resource (Skool groups) and scopes it precisely to 'groups your account belongs to, both groups you own and groups you joined.' This is clearly separable from siblings like skool_list_members or skool_get_group_stats, though the description never names a sibling explicitly.

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?

Gives concrete chaining guidance: 'Use the group field from each item as the group parameter of the other endpoints,' which tells the agent how this tool feeds downstream calls. It does not state when not to use the tool, but the context provided is substantive.

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