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

Annotations already declare destructive=true, idempotent=false, and openWorld=true; the description adds genuinely new context — the Pro-plan prerequisite, the upsert behavior on repeat calls, and the fact that the new collaborator is returned. It doesn't explain what access is granted or how to revoke it, but it meaningfully extends the annotations.

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 sentences, zero padding, with purpose and the Pro-plan constraint front-loaded. Slight redundancy in restating the role default that the schema already documents keeps it from a 5.

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 3 parameters fully documented in the schema and safety traits covered by annotations, the description supplies the remaining needed pieces: plan prerequisite, repeat-call semantics, and return value (notably useful since there is no output schema). Only the lack of sibling/alternative routing keeps it below 5.

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 only semantics the description adds (default editor, role-change on re-call) are already present verbatim in the role parameter's schema description. Baseline 3 is appropriate when the schema carries the parameter documentation.

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 (Invite/add), resource (collaborator to a Wavelength flow), and mechanism (by email with an editor/viewer role). This implicitly separates it from invite_member, add_team_member, and share_flow, but it never names those siblings to make the boundary explicit.

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 context: collaboration requires the Pro plan, and re-calling with a new role changes the existing collaborator's role rather than erroring or duplicating. It offers no explicit when-not-to-use guidance or alternative tools (e.g., add_team_member for team-level access), so it stops short of a 5.

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