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

Annotations only cover the safety quartet (readOnly=false, destructive=false, idempotent=false, openWorld=false). The description adds two genuinely non-obvious traits beyond that: the created object starts in a disabled state (a surprising default for a create call) and the URL must be public http/https with internal addresses rejected. That is real behavioral context the structured fields do not carry.

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?

Three short sentences, front-loaded with the action, then the disabled-by-default caveat, then the validation rule. No filler and no repetition — every clause carries distinct information.

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 9-parameter tool with nested objects and no output schema, the description covers purpose, the follow-up enable step, and the key input constraint. It leaves the return value (e.g. the new webhook id) and how body/body_naming templates behave unstated, though the latter is fully documented in the schema.

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 100%, and the description's URL constraint ('Адрес должен быть публичным http или https') merely restates the schema's own url description. With the schema doing the heavy lifting for all 9 params, the baseline 3 applies; no format or interaction details are added beyond the duplication.

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+resource ('Добавляет вебхук к опросу') and implicitly scopes it against the sibling webhook tools (update_quiz_webhook, toggle_quiz_webhook, delete_quiz_webhook, get_quiz_webhooks). An agent can tell this is the creation path without opening any schema.

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?

Gives an explicit workflow: the webhook is created disabled, you should first verify by sending, then enable it via toggle_quiz_webhook — the named alternative. This tells the agent both the immediate effect and the required follow-up call, which is exactly the routing information most definitions omit.

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