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

Annotations declare non-readOnly, idempotent, open-world, non-destructive operation. The description adds crucial behavioral detail beyond annotations: invitees gain manage/publish/change sharing/delete rights across the selected library, including account briefs, plus delivery semantics ('Queued is not delivered'), seven-day link expiry, and verified-email requirement.

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?

One dense paragraph that front-loads the admin restriction and core action before permission scope, prerequisites, and delivery details. Every sentence carries operational weight and nothing is wasted.

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 high-stakes invitation mutation with no output schema, the description covers permission scope, prerequisites, delivery semantics, and expiry well. The main gap is the unexplained workspace_id and idempotencyKey parameters, but annotations and schema cover types, so it is largely complete.

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 only 25%, so the description must compensate. It adds the 20-email limit and implies the confirm requirement through 'explicit user request' and 'Explain before sending', but never explains workspace_id or the required idempotencyKey, leaving critical invocation parameters undocumented.

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 action: email up to 20 addresses to join the team as Members, with admin restriction and library-level scope. It distinguishes itself through role and permission details, though it never explicitly names a sibling alternative such as invite_team.

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?

Specifies prerequisites clearly: 'Admin only', 'Requires explicit user request naming recipients and the selected brief library', and an instruction to explain scope before sending. It gives strong context for when the tool is appropriate, but does not explicitly compare against alternatives like invite_team or resend_workspace_invitation.

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