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

Annotations already declare readOnly/idempotent/non-destructive, so the bar is lower; the description adds real context beyond them: prices are computed relative to the account's current tariff and any upgrade surcharge is already included, and it clarifies the assistant cannot pay or switch (human decision). The 'read-only' statement partially restates readOnlyHint, keeping it out of 5 territory.

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?

Four tight sentences, front-loaded with what the tool returns before the usage trigger and behavioral caveats. Nothing is wasted, though the pricing sentence is slightly dense for a single-scope read tool.

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 simple read-only listing tool with no output schema, the description fully covers what is returned (tariffs, prices, periods, inclusions), the case for calling it, the pricing semantics, and the action limitation. An agent has everything needed to call it correctly.

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 single workspace_id parameter is documented in the schema (including how to obtain it). The description adds no additional parameter meaning, so the baseline 3 applies.

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?

States a specific verb and resource ('Показывает все тарифы') plus the payload the agent will receive (цены, периоды, что входит). It also implicitly distinguishes itself from the sibling get_workspace_tariff by being the full catalog rather than the current plan.

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?

Gives a concrete trigger condition — use it when you hit 'недоступно на текущем тарифе' — which is exactly the decision context an agent needs. It does not explicitly name a sibling alternative (e.g. get_workspace_tariff) for comparison, so it stops short of a 5.

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