update_contact

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

The description discloses the important behavioral trait that providing groups replaces the existing groups list. No annotations exist, so the description carries the burden. However, it does not mention whether other fields are partially updated or completely replaced, nor does it discuss authorization or side effects.

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 two sentences: the first states the tool's purpose concisely, and the second provides a key usage nuance. No fluff 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?

Given 13 parameters, no output schema, and no annotations, the description covers the group replacement behavior but lacks details on return values, error conditions, and whether unspecified fields remain unchanged. It is minimally adequate but not comprehensive.

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 coverage is 100%, so the schema already documents all parameters. The description adds context about group management ('To add/remove contact from groups'), but this largely repeats the schema's existing description ('Complete array of group IDs... (replaces existing groups)'). Thus, the description adds marginal value.

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 'Update a contact,' which is a specific verb and resource. It distinguishes from sibling tools like create_contact and delete_contact. However, it does not elaborate on which fields can be updated beyond the schema.

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 guidance on how to use the groups parameter ('provide the complete list of group IDs the contact should be a member of'), but does not explicitly state when to use this tool versus alternatives like create_contact or list_contacts. No when-not-to-use or exclusion criteria are given.

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