bitrix_update_contact

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

With no annotations, the description carries the full burden of disclosing side effects. It does state that this is a write operation, limited to certain fields, and gated by confirm=true. However, it does not clarify whether updating replaces the entire field set or merges with existing values, nor does it mention permissions, reversibility, or response behavior.

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 one compact sentence with the action, target fields, and confirmation requirement all front-loaded. It is concise and free of filler, though the incomplete field list and lack of alternative routing make it slightly less sharp than a top-tier description.

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 three-parameter update tool with a nested fields object and no annotations or output schema, this is minimally viable: the agent knows what to modify and that confirm must be true. Gaps remain around SECOND_NAME, merge-vs-replace semantics, and what the tool returns after a successful update, so it is adequate but not complete.

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 schema already documents contactId and confirm with descriptions and gives a detailed nested structure for fields. The description adds a practical list of editable fields and the confirmation requirement, but the list is incomplete because SECOND_NAME is absent, and it does not explain how the fields object should be composed for a partial update.

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 uses a specific verb, 'Изменить', identifies the resource as a contact, and lists the editable fields, which distinguishes it from contact creation, retrieval, and listing tools. However, the field list omits SECOND_NAME even though the schema allows it, so the scope is slightly inaccurate.

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 gives no guidance about when to use this tool versus bitrix_create_contact, bitrix_find_contact, or other update tools. It only states the confirm=true requirement, which is an invocation constraint rather than usage direction.

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