calendar_list

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 and scope profile is covered. The description adds the useful constraint that only enabled iCloud calendars are returned, which is real context beyond structured fields, though it omits ordering or pagination details.

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 front-loaded sentence with zero waste. Every word earns its place.

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?

Adequate for a simple zero-input list tool whose annotations carry the safety profile, but it could go further by noting the discovery role (obtaining IDs for use with calendar_read/calendar_create) and any return ordering.

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 a single empty arguments object, so there are effectively no meaningful parameters and no semantics to explain; the baseline of 4 applies since no param documentation is needed.

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 (List) and resource (enabled iCloud calendars and their IDs). It is distinguishable from siblings like calendar_search and calendar_read, though it doesn't explicitly say how it differs from them.

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?

Implies usage (enumerate calendars to obtain IDs) but gives no explicit when-to-use or when-not-to-use guidance, and does not name alternatives such as calendar_search. Discovery intent is inferable but not stated.

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