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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is covered by structured data. The description adds two things annotations do not: an authorization requirement (admin-only) and a prompt-injection caution about CRM field values being untrusted input. It does not mention result size, pagination, or ordering.

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, front-loaded with what is listed before the access constraint and the safety note. Every sentence carries content, though the injection warning is generic boilerplate that appears to be shared across the toolset.

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 read-only, one-parameter list tool with no output schema, the description covers scope, return fields, and the admin prerequisite, and annotations cover the safety profile. The remaining gap is result-shaping behavior (ordering, pagination), which is not addressed anywhere.

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 description coverage is 100%, and the workspaceId schema text already explains the multi-workspace requirement and the whoami fallback. The description adds no parameter-level detail, so the baseline 3 applies.

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 (Lists) and resource (invitations) and narrows scope precisely with 'nobody has accepted yet', which separates it from invite_member, resend_invitation and cancel_invitation. It also names the payload fields returned (role and expiry), so an agent knows what it gets without opening the schema.

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?

'Workspace admins only' gives a clear precondition for calling this tool, which is real usage context. It stops short of a 5 because it never contrasts with the nearest siblings that an agent might confuse it with (e.g. list_members for accepted members, cancel_invitation for acting on a pending one).

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