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

Annotations already declare readOnlyHint=true and openWorldHint=false, so safety is covered. The description genuinely adds result-set behavior: default upcoming soonest-first, past latest-first, and that cancelled plans are included. It omits pagination behavior and the implicit cap of 50 despite a cursor parameter.

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 tight sentence with the default behavior front-loaded and no filler. Every clause (default upcoming, sort direction, cancelled included) conveys distinct 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?

An output schema exists, so return fields need not be described, and the annotations cover the read-only profile. However, with four undocumented parameters and no explanation of role-based filtering or pagination, the definition is minimally adequate rather than complete.

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?

Schema description coverage is 0%, so the description carries the full burden, yet it only partially explains `when` (default and sort order). The `role` enum (any/organizer/invitee), `limit` bounds, and `cursor` pagination are left entirely undefined in both schema and description.

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+resource (list plans) and scopes it to the caller's own plans, adding the default ordering. It is distinguishable from get_plan (singular) and create_plan/cancel_plan, though it does not explicitly name those siblings.

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 description implies when to use it (to browse plans in either direction) and reveals the default is upcoming, but it never states when to prefer it over get_plan or how role/limit/cursor should be combined. Usage context is implied rather than explicit.

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