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

Annotations already flag openWorldHint, non-idempotent, and non-destructive, and the description adds substantial context beyond them: the invitation is address-bound, expires in 7 days, consumes a Pro seat per member and per pending invite, and surfaces a specific seat-exhaustion error with the resolution path. That is exactly the behavioral detail an agent needs before invoking an outbound-email mutation.

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?

Four short sentences, each carrying distinct information: scope, invitation mechanics, seat cost, and failure handling. The core action is front-loaded and there is no filler.

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 still covers the relevant outcome behavior by describing the expiry window and the seat-exhaustion error. Combined with a fully covered input schema and rich annotations, nothing an agent needs to call this correctly is missing.

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 100%, so org_id, email, and the role enum with its default are already fully documented in the schema. The description's 'as member or admin' only mirrors the enum values and adds no syntax, format, or sourcing detail beyond what the schema provides, 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 and resource ('Invite one person to an organization by email') and pins the scope to a single invitation, distinguishing it from siblings like add_collaborator, add_team_member, or create_organization. The role option ('as member or admin') further sharpens what the call does.

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?

Gives clear operational context: role selection, seat consumption per member/pending invite, and the error path plus remedy ('the owner adds seats in Billing'). It does not explicitly name when to prefer this over add_collaborator or add_team_member, so it stops short of full alternative routing.

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