avito_update_stock

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

Annotations already indicate readOnlyHint=false (write) and idempotentHint=true. The description adds critical behavioral details: confirm_write must be true, quantity=0 hides the 'buy with delivery' button, and the exact response shape. These go beyond the annotations and are essential for correct invocation. No contradiction with annotations.

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 well-structured: a one-line purpose with endpoint, a behavioral note, a clear argument list, and the return format. It is a bit long but every sentence adds value. The main purpose is front-loaded, and the argument details are neatly formatted.

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 simple write operation with three parameters, the description covers everything an agent needs: the purpose, the required flag, the quantity range, and the response schema. There is no missing information about prerequisites, side effects, or error handling. The output schema also exists, so the return format is redundantly specified but harmless.

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 0%, so the description carries the full burden. It explains every parameter: item_id is the listing id, quantity is the available units with a range (0..999999), and confirm_write must be true. It also clarifies that quantity 0 has a UI effect. This fully compensates for the lack of schema descriptions.

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 states a specific action ('Set the available quantity'), the resource ('ONE listing'), and even the HTTP endpoint. It clearly distinguishes from sibling tools like avito_update_price (price) and avito_get_stocks (read). No ambiguity about what the tool does.

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 action itself makes the usage context clear: it's for setting stock quantity, not for price or reading. While it doesn't explicitly name alternatives, the purpose is so unambiguous that an agent would know when to invoke it. There are no exclusion criteria, but none are needed given the specific verb-resource pairing.

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