update_contact

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

With no annotations, the description must fully disclose behavioral traits. It only says 'update' implying mutation, but does not mention whether updates are partial or full, required permissions, error handling, or side effects. This is insufficient for safe invocation.

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?

Extremely concise (one sentence) but at the expense of completeness. While every word earns its place, the description fails to provide necessary details, making it more under-specified than efficient.

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 one parameter with zero description coverage and no annotations, the description is woefully incomplete. It does not explain the return value (though an output schema exists), valid inputs for kwargs, or any constraints. The tool cannot be safely used.

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 sole parameter 'kwargs' has no description in the schema (0% coverage), and the description provides no additional meaning. The agent has no idea what keys or values are expected, severely limiting the tool's usability.

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 'Update a personal contact' is a clear verb+resource statement. It identifies the action (update) and the target object (personal contact). However, it does not differentiate from sibling tools like update_event or update_contact's specific scope.

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 on when to use this tool versus alternatives like create_contact, delete_contact, or search_contacts. The description lacks any context about prerequisites, required IDs, or typical use cases.

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