Groups

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety is covered. The description's one behavioral addition is the default scope ('default: this account'), which is real value. It says nothing about pagination behavior, whether private groups appear, or what identity is used for user_groups/joined.

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?

Very short — almost no waste — but the structure is a single telegraphic fragment with a nested parenthetical ('joined; default: this account'), which is harder to parse than two clean sentences would be. Compact but not well-formed.

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 should say something about what a returned group looks like, and it does not. It also omits which fields are needed for each type variant. Adequate to pick the tool, insufficient to call it confidently for all three modes.

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 60% and the enum on `type` has no schema description at all, so the description is doing real work here: it glosses all three enum values and ties `genre` to type=genre. It leaves `user_id` and page/count behavior unaddressed, which keeps it below 5.

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 sentence names the resource (groups) and enumerates what the returned groups are keyed by (genre / user_groups / joined), which is genuinely informative. But it is a sentence fragment with no verb, and it reads as a note about the `type` parameter rather than a statement of 'list groups matching a filter'. An agent can figure out the purpose, but only by inferring.

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 implies when each variant applies and gives the default ('this account'), which is useful selection guidance. It never names an alternative — e.g., get_group for a single group — nor states prerequisites like 'genre slug required when type=genre', so the agent must derive those from the schema.

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