List Counters

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

With no annotations, the description carries the full behavioral burden. It discloses that the operation lists only counters accessible to the token, returns each counter's id/name/site, and requires only read scope. This goes beyond the tool name and schema, though it omits details like pagination or error behavior, which are less critical for a list-all endpoint.

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 concise sentences. The first sentence states the core purpose; the second explains the output fields and their downstream use. There is no wasted wording or redundancy, and the essential information is front-loaded.

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?

The tool is simple (no parameters, no nested objects) and an output schema exists, so the description does not need to describe return structure. It covers what the tool does, what it returns, how to use the result, and the required scope. Nothing essential is missing for correct invocation.

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 tool has zero parameters, so schema coverage is trivially 100%. The description adds relevant context about the output fields (id, name, site) and their purpose, which helps the agent interpret the result. With no parameters to document, a baseline of 4 is appropriate.

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 verb ('List'), a clear resource ('Yandex Metrika counters'), and scopes it to those 'available to the token.' It also implicitly distinguishes itself from the sibling 'query' by positioning the output as a way to pick a counter_id for query.

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 provides clear context: use this tool to obtain counter ids/names/sites, then feed a selected counter_id into 'query.' It does not explicitly state 'when not to use' or name alternatives, but given the single sibling and the dependency hint, the intended usage is apparent.

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