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

Goes well beyond the annotations by disclosing a destructive side effect ('the old link stops working'), the authorization requirement (Owner or Admin), and a security-sensitive response trait: when no mail is sent, the new link is returned and must not be shared beyond the person it is acted for. That last point is exactly the kind of context annotations cannot carry.

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 tightly packed clauses, front-loaded with the action and effect, then the UI/auth anchor, then the link-handling caveat. No filler text and nothing repeated from the schema or annotations.

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 correctly compensates by explaining the conditional return value (the new link when no mail goes out). Auth, destructive effect, and the distinction from creating an invitation are all covered, so an agent has everything needed to call it safely.

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 single parameter is fully documented in the schema ('The invitation's id, as list_members returns it'). The description adds no syntax, format, or sourcing detail beyond what the schema already provides, so the baseline of 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?

Specific verb ('resend'), specific resource ('pending invitation'), and the concrete effect ('fresh link; the old link stops working'). It also anchors the tool by naming the UI equivalent ('Resend invitation on a pending row of Settings › Members'), which separates it cleanly from the create-oriented sibling invite_member.

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 context is clearly bounded to pending invitations and the caller requirement is stated ('needs Owner or Admin'). It does not explicitly name invite_member as the alternative for non-pending cases, so the when-not path is only implied rather than spelled out.

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