things_schedule_item

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

Annotations already declare readOnly=false, destructiveHint=true, and idempotentHint=true; the description adds useful behavioral context by specifying Mac-timezone interpretation, the need for the current revision, and the fact that reminders and repeating rules are not set. No contradiction with annotations exists.

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?

Three short sentences, front-loaded with the core operation, then preconditions, then behavioral limitations. Every sentence earns its place and there is no redundant or filler content.

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?

Given the nested target object, rich annotations, and an output schema, the description covers the core operation, prerequisites, timezone, and non-goals. It is sufficient for correct invocation, though explicitly naming an alternative for reminders or repeating rules would make it more 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?

With 0% schema description coverage, the description compensates by mapping all core parameters to concepts: to-do/project maps to target.kind, current revision to expectedRevision, unique UUID to requestId, and explicit calendar date to date. It adds semantic value beyond the raw schema, though it does not detail every nested field.

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: 'Schedule a to-do or project on an explicit calendar date in the Mac timezone.' This clearly distinguishes the operation from siblings like move/trash, though it does not explicitly contrast it with things_update_item.

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?

Provides prerequisites ('Requires its current revision and a unique UUID requestId') and a limitation ('Does not set reminders or repeating rules'), so an agent has context for when this is appropriate. However, it does not name an alternative tool or give an explicit when-not-to-use condition for scheduling versus updating.

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