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

With no annotations, the description must carry the behavioral load; it does disclose the default date window (7 days), which is genuine behavioral information beyond the schema defaults. It says nothing about permissions, limits, or what grouping does to row counts, and leaves the mutation/read distinction to be inferred from 'Получить'.

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?

Two tight sentences with the capability stated first and the fallback behavior second. Nothing is wasted and the key 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?

For an 8-parameter analytics tool with no annotations, the description is thin: output schema existence covers return values, but there is no guidance on how metrics/dimensions interact with grouping or how this differs from the other Metrika reporting siblings. Adequate to call, not fully adequate to call correctly on the first try.

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 coverage is 100%, so every one of the 8 parameters is already documented in the schema. The description adds only the group enum values and the date default, which the schema already states; it adds no meaning for metrics, dimensions, or top_keys beyond the schema.

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?

Names a specific verb and resource: retrieve Yandex.Metrica data grouped by time, with the grouping granularities enumerated. It distinguishes itself from siblings like get_metrika_visits or get_metrika_custom_query only implicitly via the 'grouped by time' framing; there is no explicit contrast with those tools.

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?

Provides one concrete usage rule — 'if dates are not specified, data for the last 7 days is returned' — which helps the agent decide it can be called lazily. However, it never states when to prefer this over the many sibling Metrika tools (custom_query, visits, pages_report, sources_summary), leaving the selection decision to inference.

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