update_contact

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

The description only says 'Update' which implies mutation, but no annotations are provided. It does not disclose side effects, authentication requirements, rate limits, or whether updating customFields merges or replaces. Behavioral transparency is minimal.

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 sentence, no redundant words. It is front-loaded with the verb and resource, making it 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?

No output schema is provided, and the description does not explain return values or error handling. The tool updates multiple field types, but the description lacks context on validation, merging behavior for custom fields, or confirmation of success.

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 description coverage is only 33%, so the description must add meaning. It groups parameters into categories (profile fields, custom fields, subscription state), which helps but does not explain individual parameter formats or constraints. It adds some value but is insufficient for the undocumented parameters.

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 it updates a contact's profile fields, custom fields, or subscription state. The verb 'Update' and the resource 'contact' are explicit, and the categories distinguish it from other tools like create_contact or delete_contact.

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 no guidance on when to use this tool versus alternatives. No mention of prerequisites, exclusions, or comparison with sibling tools like add_contacts_to_audience or search_contacts.

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