upsert-my-preference

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

Without annotations, the description carries the full burden. It states the upsert nature ('Create or update') but does not disclose idempotency, overwrite behavior, required authentication, or side effects. This is comparable to the update_drive example in the calibration, which scored 2.

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 a single, efficient sentence that front-loads the essential information. There is no unnecessary wording or repetition.

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?

The tool is simple but has no output schema and no annotations. The description does not explain what constitutes a valid preference, whether keys are predefined, or what the response looks like. This is insufficient for an agent to confidently invoke the tool without additional context.

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 descriptions cover 100% of parameters, but they are minimal ('Preference key.' and 'Preference value.'). The description adds no parameter information, so the baseline of 3 applies. However, the value parameter's lack of type is not addressed by either the schema or the 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?

The description clearly states the action ('Create or update') and the resource ('preference for the current user'), distinguishing it from siblings like get-my-preferences and delete-my-preference, as well as admin variants.

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?

No guidance is provided on when to use this tool versus alternatives. It does not mention that it is for setting one's own preferences, nor does it point to admin-upsert-user-preference for managing other users' preferences.

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