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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so safety is covered. The description adds genuinely non-obvious behavioral context beyond that: no point is a birth-rate forecast because the children are already born and counted, and migration is excluded from the numbers. These data-semantics caveats are the kind of context an agent cannot get from the schema or annotations.

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 resource is front-loaded, then the returned fields are enumerated after a colon, followed by two clarifying constraints. It is somewhat long, and the 'not a forecast' point is restated across two sentences, but given no output schema exists the added length is largely justified.

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?

With no output schema, the description carries the burden of describing return values, and it does so by enumerating the row fields and the horizon (2038). The single required parameter is covered. What is missing is pacing/volume or how the corridor is bounded, but the definition is largely complete for a one-parameter read tool.

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 schema already documents the single 'субъект' parameter including the code-or-name distinction and an example (62). The description's 'Субъект задаётся кодом или названием' merely restates the schema, so baseline 3 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 names a concrete resource and its content: a per-region series of sixteen-year-olds up to 2038 with the fields it returns (year of admission, year of birth, generation size, actuals, corridor). It is clearly not an admission-plan tool, which implicitly separates it from outcome/planning siblings, but it never names a sibling such as regions_by_indicator or territory to disambiguate explicitly.

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?

Scope-limiting statements ('это демография, а не план приёма', 'миграция не учитывается') tell the agent what the tool is not for, which is useful negative guidance. However, it never states when to choose this tool over alternatives or what preconditions apply; usage remains implied by the resource description.

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