update_planner_options

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

No annotations are present, so the description carries the full burden. It states that preferences are updated, but it does not disclose side effects, whether the update is a partial merge or full replacement, authentication requirements, or error behavior.

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 description is brief, front-loaded with the core purpose, and provides only essential examples and guidance. No filler or redundant 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?

It gives enough to start using the tool, but important practical details are missing: how preferences are applied (merge vs replace), whether nested keys are required, and what response or errors to expect. The 'Rarely needed' note adds some context but not full operational clarity.

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 schema itself provides no descriptions, but the description compensates with concrete allowed keys, value types, and Rails-style nested key examples like user[time_zone] and calendar_settings[show_calories]. It does not enumerate every possible option, but the 'etc.' is acceptable given the arbitrary object shape.

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?

Clearly states the action ('Update') and the resource ('planner display/behaviour preferences'), with concrete examples such as time_zone, planner_start_day, and calendar_settings.show_calories. It is distinct from other planner-related sibling tools, which target entries, events, or servings rather than preferences.

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 some usage context by saying 'Rarely needed' and showing the nested-key format, but it does not explicitly state when to use this tool versus alternatives, nor does it give exclusions or edge cases.

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