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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=true, so the safety profile is known. The description adds genuinely new context: the full scope of returned events (everything the account can open, as owner or collaborator) and the auth requirement, which the annotations do not cover.

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?

Short and front-loaded, leading with the resource and scope. The ownership/collaborator scope is stated twice ('events you own or collaborate on' and 'as owner or collaborator'), a minor redundancy, but the whole thing is compact and every remaining sentence carries unique information.

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 list tool with no output schema, the description supplies the resource, scope, returned fields, the chaining hint to other endpoints, and the auth prerequisite. An agent has everything needed to invoke it and use its results correctly.

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?

There are zero input parameters, which is the baseline-4 case; no parameter explanations are needed. The description's mention of event_id is about downstream tool usage rather than this tool's own inputs, and it correctly clarifies there is nothing to pass in.

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 ('List events') plus the exact scope (events you own or collaborate on) and the fields returned (name, date, website URL), so an agent knows precisely what comes back. It is clearly distinguishable from the other Joy tools, which act on guests, registries, and schedules rather than the event list itself.

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 context for use, including the workflow hint that each item's event_id feeds the event_id parameter of the other endpoints, and the prerequisite of a Cotlet API key with app access. It stops short of naming explicit alternatives or when-not-to-use conditions, so it is strong but not fully routing.

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