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

Annotations already flag this as a non-idempotent, destructive, open-world write; the description adds real value by naming the failure conditions (missing email, invalid inviter, already a member) returning 422. It omits auth requirements and rate limits, keeping it short of a 5.

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 dense clauses with the essentials (action, required fields, default, errors) front-loaded, plus a docs link. No filler, though the density sacrifices some readability.

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?

An output schema exists so return shape needn't be described, and the error behavior plus required-field semantics cover what an agent needs to invoke correctly. Missing only permissions/auth context for a destructive write.

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?

Reported schema coverage is 0%, so the description must carry the load, and it does: it names the required nested fields, clarifies inviter_email must be an existing member, and states access defaults to 'standard'. It doesn't explain the admin/standard semantic difference or format constraints beyond what's obvious.

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 a user by email') that is unambiguously distinct from the read siblings like get-invitation and list-invitations. The required-field callout reinforces exactly what the tool creates.

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?

Usage is implied by the creation verb and the prerequisites, but the description never says when to prefer this over related flows (e.g., resending or listing invitations) or what happens if an invitation already exists rather than a 422 case.

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