Update Relay Contact Card

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

Annotations already indicate this is a mutating, non-idempotent operation, so the description does not need to restate that. It adds modest behavioral context by specifying 'selected fields' and scoping to the authenticated agent, but it does not disclose whether unspecified fields are preserved, how image_url null is handled, or what side effects occur.

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, front-loaded sentence with no filler or repetition. It is concise, though it sacrifices useful detail for brevity.

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 mutating tool with no output schema and zero schema description coverage, the description is too sparse. It omits key context such as parameter roles, partial-update semantics beyond the phrase 'selected fields', and how this relates to the contact card sibling tools.

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 input schema has no descriptions for any of the four parameters, so the description must compensate by explaining or enumerating them. It does not mention handle, image_url, first_name, or last_name at all, leaving the agent to rely only on parameter names and constraints.

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 a specific action ('Update') and resource ('authenticated Agent's Contact Card'), and the phrase 'selected fields' implies a partial update. However, it does not explicitly differentiate this from the sibling relay_set_contact_card, so an agent must infer the distinction.

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 implies this tool is for partial updates to the authenticating agent's own contact card, which is a useful usage signal. It does not explicitly state when to prefer this over relay_set_contact_card or other siblings, nor does it mention any exclusions or alternatives.

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