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

Goes beyond the destructiveHint/openWorldHint annotations by disclosing the concrete destructive semantics: re-inviting the same address replaces the pending invitation of the same kind (site invitations only when the site set matches exactly) and re-sends the email, and the tool returns exactly who was emailed. Authorization constraints are given. It stops short of describing what happens to the replaced link or delivery failures.

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?

Front-loaded with the use-case trigger, then mode, then side effects, then permissions, then the exclusion. Some sentences are long, but every clause carries decision-relevant information, including the replacement rule that would otherwise be a surprise.

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 destructive, open-world, no-output-schema tool with 7 parameters, the description covers trigger, modes, return value ('returns exactly who was emailed'), side effects, authorization and the sibling alternative. Nothing an agent needs in order to call it 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 the baseline is 3, but the description adds the mode-selection logic the schema only implies: role/scope for an account invitation versus sites/level/site_checks for a monitor-only invitation. That distinction is the main thing an agent can get wrong, and it is stated in prose.

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?

A specific verb and resource ('invite a person to their FlareWarden account') with both operating modes spelled out: a teammate at a role, or a client with a monitor-only invitation on selected sites. It explicitly excludes the nearest sibling ('Not for changing the role ... use change_member_role'), so an agent can pick it without reading other schemas.

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?

Opens with an explicit when-to-use trigger ('Use this when the user wants to give a person access'), states prerequisites (owners and admins only, an admin cannot invite an admin) and names the alternative tool for the adjacent case. The only gap is it doesn't point at revoke_invitation for the inverse operation, which is a minor omission.

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