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

Annotations already establish readOnly, idempotent, non-destructive, closed-world behavior, so the bar is lower. The description still adds real value beyond them: it explicitly states the tool "opens nothing by itself" (no side effects despite the action-oriented name) and discloses Joy's integration landscape - no public API, no developer program, no Zapier app - which heads off an agent attempting an API route.

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 and dense: what it returns, that it performs no action, and which tools to use next all appear in the first two clauses. The closing API/Zapier note is somewhat tangential but earns its place by preventing a dead-end integration attempt. No filler sentences.

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 zero-parameter, read-only guide tool with no output schema, the description covers the essentials: the return content (step-by-step screens, buttons, fields), the absence of side effects, and the follow-on tooling. It does not describe what happens if the user is not signed in to Joy, but nothing critical to correct invocation 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?

The tool takes zero parameters, so the baseline is 4; there is no parameter meaning left for the description to supply and additionalProperties is false, meaning the call surface is unambiguous.

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 opening sentence promises the same verb+resource as the name ("List guests in the user's own Joy account"), but the follow-up reveals the tool does not return guest data at all - it "Returns how to do it in Joy step by step (screens, buttons, fields)". That clarification is honest and useful, but the bait-and-switch framing against the name means an agent could invoke it expecting a guest list and get instructions instead.

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?

The two-phase workflow is implied clearly enough: call this to get the steps, then execute them "with the cotlet_browser_* tools in the user's Joy Cloud Browser". However, there is no guidance on when to prefer this over cotlet_app_guide (generic sibling) or joy_get_rsvp_status, nor any exclusion stating when this tool is unnecessary.

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