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

Annotations already declare readOnlyHint=true and idempotentHint=true, covering the safety profile. The description adds meaningful behavioral scope: 'your' indicates user-scoped listing, and 'pending invitations' discloses that the response also includes invitations, which is not inferrable from annotations or the tool name alone.

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?

The description is a single, front-loaded sentence: 'List your groups and pending invitations'. Every word earns its place; no filler, no redundancy. It efficiently conveys the full purpose in just seven words.

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?

Given the tool's simplicity (0 parameters, no output schema), the description fully covers what an agent needs to know: the action (list), the resource (groups), the scope (your), and the inclusion of pending invitations. The annotations cover safety and idempotency. No critical information is missing for correct 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?

There are 0 parameters and schema coverage is 100%, so the input schema has no burden. The description correctly avoids adding any parameter details, meeting the baseline for a zero-parameter tool. No further parameter explanation is needed.

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: 'List your groups and pending invitations'. It clearly distinguishes from sibling tools like groups_read (single group) and groups_create/update by its list semantics. The inclusion of 'pending invitations' adds specificity beyond the name alone.

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?

The description implies usage ('list your groups') but does not explicitly state when to choose this over alternatives like groups_read or groups_search. The title 'Browse groups' reinforces intent, but there is no mention of exclusions or a decision rule based on need for a single group vs all groups. Usage is implied rather than explicit.

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