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

With no annotations, the description carries the disclosure burden. It conveys that this is a comparison/report over previously captured check data, not a mutation or a new check trigger, and it exposes the no-group fallback behavior. It leaves limit semantics and the no-previous-check edge case undisclosed, but the core behavioral profile is clear.

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 compact and wastes no words, front-loading the purpose and then listing result categories. It is slightly telegraphic ('Что изменилось...', 'Без группы — по последней проверке'), but it earns its length.

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 two-optional-parameter report tool, the description covers the main purpose, output categories, and the group default, and an output schema exists to describe return values. The limit parameter is entirely unexplained and the no-previous-check case is not addressed, so the definition is minimally viable but has a clear gap.

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 0%, so the description is the only source of parameter meaning. The final clause gives some meaning to group (optional; fallback to the last check), but nothing is said about limit, an integer parameter that likely caps how many results are returned. The compensation for missing schema descriptions is therefore incomplete.

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 defines a concrete outcome: report what changed for tracked products since the previous check, and it lists the exact change categories (price with old/new/percent, availability, sales scheme, rating, new items). This makes it clearly distinguishable from sibling price/status tools in spirit, though it never names a specific sibling.

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 implies when to use the tool: when the agent needs a delta report since the last check, and it explains the behavior when group is omitted. It does not, however, tell the agent when to prefer this over parsee_get_prices, parsee_price_history, or parsee_spp_changes, nor does it state exclusions.

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