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

Annotations already provide readOnlyHint=true, and the description adds meaningful behavioral context beyond that: guests are non-workspace members with limited view/download scope, and the response contains invited guests and their status. No contradiction with the annotation.

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 short sentences, no filler. The key questions are front-loaded, and each sentence adds distinct value: purpose, return value, and domain semantics.

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 simple one-parameter, read-only list tool with no output schema, the description is complete: it states what the tool returns, the scope of the data, and the semantics of the listed entities. An agent has enough to invoke it correctly.

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 schema has one undocumented 'id' parameter (0% description coverage), but the description and title repeatedly refer to 'this collection', making the id's referent clear. For a single obvious parameter, the contextual inference is sufficient.

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 opens with concrete questions ('who has access... who did I invite... has someone accepted?') that precisely frame the tool's verb and resource. It also defines guests as not workspace members, which clearly separates this from sibling tools like list_contacts or get_account.

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 question-based framing gives clear context for when to use this tool: whenever the agent needs guest access or invitation status for a collection. It does not explicitly name alternatives or when-not conditions, but the guest-vs-workspace-member distinction implies the boundary.

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