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

Annotations already declare readOnlyHint=true and openWorldHint=false, so safety is covered. The description adds meaningful behavioral context beyond that: the data is a snapshot comparison against the previous crawl, and it defines the thresholds used (e.g. price drops of 10% or more), which helps the agent interpret results. It does not cover pagination or result limits, keeping it short of a 5.

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 sentences, front-loaded with the core comparison and then the filter clause; the enumeration of change types is dense but earns its place by telling the agent what will be returned. No filler.

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 read-only, no-output-schema tool with fully documented optional params, the description covers what the tool aggregates and the comparison window. Minor gaps remain (whether country and category can be combined, response shape), but nothing essential for invocation is missing.

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%, so the baseline is 3. The description restates that filters are optional and scoped to one category or country, but adds no format or combination semantics beyond what the schema already documents.

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 ('Totals and examples from the latest weekly crawl compared with the previous one') and enumerates the change types covered (product launches, price drops, discounts, best-seller climbs, app store additions). This is clearly distinguishable from the store-lookup siblings (find_stores, lookup_store, technology_usage).

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 'Optionally for one category or country' clause implies scoping usage, but there is no explicit when-to-use guidance, no comparison against sibling tools, and no note on when the weekly snapshot is or isn't appropriate. Usage is only implied.

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