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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds real value by disclosing scope and data-quality caveats: it returns the couple's own question definitions and explicitly surfaces answers that could not be matched to a guest. It says nothing about volume, ordering, or whether the dietary list is deduplicated for the caterer.

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?

A single sentence front-loads the intent ('Where the RSVPs stand') and then spends the rest on a tight comma-separated inventory of outputs. The parenthetical '(kind, options, whether required)' is the only nested detail and it earns its place by describing question structure.

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 present, the description carries the burden of describing return values and does so category by category, including the unusual unmatched-answers case. It stops short of stating whether the summary spans the whole wedding versus a single moment, which is the one scope ambiguity left for an agent.

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?

The tool takes zero parameters, so there is nothing for the description to disambiguate; the baseline for a no-parameter tool applies. The description correctly implies a global, unfiltered scope by describing the summary as covering all moments and all unmatched answers.

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?

The description opens with 'Where the RSVPs stand' and then enumerates the exact payload: per-moment counts, dietary list, guest messages, the couple's RSVP questions with answers, and unmatched answers. That is a specific, recognizable resource even though it never uses an explicit verb like 'retrieve' and does nothing to contrast itself with get-guest or search-guests.

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?

There is no when-to-use or when-not-to-use guidance and no named alternative. An agent must infer from the content list that this is the aggregate RSVP report rather than a per-guest lookup, and nothing tells it which sibling to pick for individual guest RSVP status.

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