update_mylist_part

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

The description adds the key behavioral nuance of preserving omitted fields, which is not captured by the annotations. Yet it leaves ambiguity about whether explicitly setting a field to null clears it versus omitting it, and it does not address authorization or state requirements beyond 'approved.' With annotations already indicating idempotent and non-destructive behavior, the added value is moderate.

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, focused sentence that immediately states the action and the key preservation behavior. No filler, redundancy, or unnecessary detail—ideal conciseness.

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?

Despite a complex nested request object and no output schema, the description is minimal. It fails to explain the 'approved' concept, how to obtain list_id/unique_id, the response structure, or the null-vs-omitted distinction. Significant context is missing for an agent to invoke the tool confidently.

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 has zero description coverage for its 14 request fields, and the description does not enumerate or explain any of them. It only refers generically to 'every field omitted,' forcing the agent to rely on schema types and defaults without guidance on relationships or conditional logic.

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 (update) and the specific resource (an approved MyList part), and the phrase 'while preserving every field omitted from the request' distinguishes it from a full replacement update. This sets it apart from sibling tools like remove_mylist_part or add_parts_to_mylist.

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 provides clear context about a partial-update scenario by emphasizing preservation of omitted fields, which tells the agent when this tool is appropriate. However, it does not explicitly name alternatives or state when not to use it, and the 'approved' requirement is mentioned but not elaborated.

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