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

With no annotations supplied, the description carries the full burden and does meaningful work: it discloses the naming convention ("vebhost - " prefix), the account prerequisite, and a non-obvious destructive side effect (the old counter is deleted when the address changes). It stops short of describing idempotency when a counter already exists, error behavior, or the returned value.

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 and ending with the side effect. Every sentence contributes distinct information (purpose, naming, prerequisite, destructive behavior) with no filler.

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 mutation tool with no annotations and no output schema, the description covers the risky parts well, including the deletion of an old counter and the required linked account. It is still incomplete because the sole input parameter is left ambiguous, which is the one thing an agent must get right to call it successfully.

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 single parameter slug is documented at 0% coverage in the schema, and the description never names it or states its format. "Для текущего адреса сайта" only loosely hints that the site address is the input, leaving the agent to guess whether slug is a domain, a site ID, or a slug string.

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 names a specific verb ("Создать") and a specific resource ("счётчик Яндекс.Метрики") scoped to "текущего адреса сайта", so an agent immediately knows this provisions a Metrika counter for the current site. It is clearly distinguishable from the sibling vebhost_metrika_delete, which removes counters rather than creating them.

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?

A prerequisite is stated explicitly (a Yandex account connected in the dashboard), which implies the condition under which invocation will succeed. However, there is no statement of when to prefer this over related siblings such as vebhost_analytics or vebhost_webmaster, and no when-not guidance is given.

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