Contacts API: Update a contact

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

Annotations already declare the safety profile (readOnlyHint=false, idempotentHint=false, destructiveHint=false, openWorldHint=true), so the bar is lower. The description goes beyond them usefully by disclosing the extra_body merge mechanism and the fact that text is sent unchanged with Persian/Arabic-Indic digit support. It still omits whether unspecified fields are left intact (partial vs full update), which matters for a PATCH.

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?

Front-loaded with the action and endpoint, followed by the body-field inventory and one encoding caveat; nothing is padded. The body-field enumeration is the weakest part since it repeats the schema, but it is brief.

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 exists, so return values need not be described, and all ten parameters are documented in the schema. What is missing is update semantics (partial vs full replace), auth/permission expectations, and any sibling disambiguation for a tool with several near-identical update neighbors.

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 baseline is 3; the description lifts it by naming the accepted body fields as a set, explaining how extra_body carries unlisted keys, and adding an input-format rule for identifiers/numbers/phone numbers (Persian or Arabic-Indic digits). The field list itself is largely redundant with the schema.

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?

States a specific verb and resource ('Update a contact's attributes') and pins down the exact HTTP method and path, so the agent knows this is an inbox-scoped PATCH. It does not, however, differentiate itself from the sibling gapify_update_contact, leaving the agent to infer which contact-update variant applies.

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 when-to-use guidance, no statement of prerequisites (e.g. needing the inbox identifier from the inbox channel), and no routing to or away from the sibling gapify_update_contact or gapify_get_contact. The only context is the raw endpoint path, which the agent must interpret on its own.

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