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

This is the strongest element: the description pre-empts the apparent mismatch between the name 'update' and readOnlyHint=true by stating the tool 'opens nothing by itself' and only returns guidance, which is genuinely useful context. It also discloses the absence of a public API, developer program and Zapier app, explaining why the browser path is required. It stops short of describing how the returned steps are formatted or how long they are.

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?

The core scoping is front-loaded in the first sentence and the no-API note is appended as reference context. The phrasing is somewhat dense with parentheticals and the dated claim, but nearly every clause carries routing or behavioral value.

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 parameters and no output schema, the description carries the burden of explaining what comes back and does so (step-by-step screens, buttons, fields) plus the required follow-up tool family. What remains missing is how much detail the steps contain and whether the agent should expect a single event or a general procedure.

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 and there is nothing for the description to clarify parameter-wise. No misleading parameter hints are introduced.

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 names a specific verb and resource (update event details in the user's own Joy account) and immediately clarifies the actual deliverable: step-by-step Joy instructions with screens, buttons and fields. It also distinguishes itself from the execution path by naming the cotlet_browser_* sibling family, though it does not differentiate itself from joy_* siblings like joy_add_guest or joy_list_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?

Usage is implied through a clear two-step workflow: call this first to get instructions, then act via cotlet_browser_* in the Joy Cloud Browser. However, there is no explicit when-not guidance and no statement of why an agent would pick this over cotlet_app_guide or the other joy_* tools, so the agent must infer the routing.

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