top_merchants

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

No annotations are provided, so the description carries the full behavioral burden. It does not disclose ordering (presumably descending by spend), what happens when month is omitted, or the fact this is a read-only aggregation — all relevant for a ranking tool whose date scope is implicit in 'за месяц'.

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?

A single short sentence with zero padding, front-loading the resource and the ranking criterion. It is efficient, though it could have spent one more clause on routing or parameters without becoming bloated.

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?

An output schema exists, so return values need not be described, but with no annotations and 0% schema coverage the two parameters are entirely unexplained in the definition. For a low-complexity aggregation tool this is the main missing piece and it is a significant one.

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 neither parameter is documented anywhere: 'n' has no meaning attached to it and 'month' has no stated format or default behavior. The phrase 'за месяц' hints that a month can be scoped, but gives no syntax to fill the gap.

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 resource (merchants / shops and services) and a ranking criterion (most money spent in a month), which is enough for an agent to know what the tool returns. It does not explicitly contrast itself with the closest sibling spending_by_category, so the merchant-vs-category distinction is only inferable from the noun.

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?

It states what the tool shows but never says when to prefer it over spending_by_category, search_transactions, or find_subscriptions, and gives no prerequisites or exclusions. The agent must infer routing from the name alone.

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