import_contacts

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

Annotations already indicate readOnlyHint=false, consistent with an import operation. The description adds the key input requirement (phone numbers without Telegram-ID), but does not disclose what happens on duplicates, whether it overwrites existing contacts, or any failure behavior. More context would be valuable for a mutation tool.

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 sentences: first states the purpose, second defines the argument structure. No filler, front-loaded, and every word contributes.

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 bulk import tool, the description gives the core purpose and input format, but lacks details on handling of existing contacts, phone number format, or result/error behavior. The existence of an output schema helps with return values, but the behavioral gaps remain.

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 only says contacts is an array of objects with string properties, and coverage is 0%. The description compensates by specifying the intended keys ('phone', 'first_name', 'last_name'), providing essential meaning beyond the raw 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?

The description uses a specific verb ('импорт') and resource ('контакты') with a clear method ('по номерам телефона'), and explicitly differentiates from siblings by noting it does not require Telegram-ID, distinguishing it from add_contact.

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 clearly implies the bulk import scenario and the condition of phone-based contacts without Telegram IDs. While it doesn't explicitly name alternative tools, the context of 'массовый' and the mention of phone numbers effectively communicates when to use it vs. single-contact operations.

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