Update contact

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

No annotations are provided, so the description must carry the burden. It discloses the method (PATCH) and partial update behavior, but omits details like authentication requirements, error handling, or whether updates are reversible.

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 concise at two sentences, with no filler. It effectively conveys the core action and the partial update approach. The structure could be slightly improved by front-loading the PATCH method.

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?

With 11 parameters, no output schema, and no annotations, the description is incomplete. It doesn't mention return value, success conditions, or common parameters beyond 'fields'. More context is needed for a complete understanding.

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 only 9% (only contactKey has a description). The description only mentions 'fields' generally and does not explain the meaning or use of the remaining 10 properties. It fails to compensate for the low schema coverage.

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 an existing person contact via PATCH, specifying partial update. It distinguishes from create_contact (new) and get_contact (read) by emphasizing 'update fields' and 'existing'.

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 advises 'Only include the fields you want to change', which guides partial update usage. However, it does not explicitly contrast with sibling tools like create_contact or get_contact, but the purpose implies when to use.

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