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

Annotations already cover the safety profile (readOnlyHint, idempotentHint, destructiveHint=false), and the description adds useful scope context: it is the caller's OWN invite, unbound to any alarm, and it lists the returned artifacts including the card image address. It adds meaning beyond the annotations, though it omits any note on permissions or freshness of the code.

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 action and scope, and every clause carries information; the nesting in "invite card picture (their handle, a QR code to the link and their code) with its address" is dense but self-explaining. Slightly overlong as a single sentence.

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 must (and largely does) describe the returned payload in detail. Combined with the annotations covering safety and idempotency, an agent has enough to call it correctly; only minor gaps remain around permissions or link expiry.

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?

Zero parameters and 100% schema coverage, so the schema carries no semantic burden. The description correctly adds no param detail, though it could have clarified that no arguments are needed for this identity-scoped read.

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 ("Gets the person's own invite to LFG Alarm") and immediately scopes it as "not tied to any alarm," separating it from alarm-related siblings. It also enumerates the concrete contents returned (invite link, referral code, message, invite card picture with address), so an agent knows exactly what this tool yields.

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 when-to-use ("For the person's own invite to send") and an exclusion ("using someone else's code is separate"), which implicitly routes to use_invite_code. It does not name the alternative tool explicitly, so it falls just short of full routing guidance.

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