update-contact

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It does clarify that this is a partial update ('Only the provided fields change'), but it omits other critical behavioral aspects such as required permissions, whether updates are reversible, what the response contains, or potential 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 short, focused sentences. Every word earns its place; 'Only the provided fields change' adds meaningful partial-update context. There is no fluff or unnecessary detail.

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?

For a tool with 5 parameters, a required contact_id, and no output schema, the description is far too sparse. It does not mention return values, required contact_id usage, error handling, or any contextual prerequisites, leaving significant gaps for an agent to make correct calls.

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 low (only contact_id has a description), and the description does not compensate. It says 'Only the provided fields change' implying any of the fields can be updated, but it does not list or explain parameters like email, phone, or names. Agents must infer semantics from property names alone.

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 identifies the verb and resource, distinguishing it from sibling tools like get-contact, list-contacts, and create-contact. However, it lacks specificity about which fields or any special scope, making it clear but not exceptionally detailed.

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?

There is no guidance on when to use this tool versus alternatives. The phrase 'Only the provided fields change' hints at partial update semantics, but does not state when this tool is appropriate, prerequisites like contact existence, or when to prefer create-contact or other update variants.

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