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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint and destructiveHint=false, so the safety profile is covered. The description adds two things annotations cannot: the data provenance (same feed as the Prickelly deals page) and the recency bound (last 7 days), plus the no-auth requirement. It does not mention result volume, pagination, or refresh cadence, so it is not fully transparent.

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?

Three short sentences, with the core definition front-loaded and each clause contributing distinct information: what, how recent, optional filter, auth requirement. No filler or restated title.

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 four-optional-parameter read-only list tool with no output schema, the description supplies provenance, freshness window and auth expectations, which is most of what an agent needs to call it safely. The main remaining gap is what a returned 'deal' contains (price, discount, link) and whether results are ordered, which the description leaves unstated.

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 every parameter is already documented in the schema, including the marketplace values and the 1-20/default 8 limit. The description only restates the marketplace filter ('Optional marketplace filter') without adding syntax or behavior, which is the baseline case.

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 ('List current real price drops') and pins the scope to a concrete source and a 7-day recency window, which separates it from get_price_history and search_products in spirit. It stops short of naming a sibling and the condition that would select it, so the differentiation is implied rather than explicit.

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 7-day window and 'same source as the Prickelly deals page' imply this is a browse-curated-deals tool rather than a search tool, and 'No sign-in required' removes a usage prerequisite. However, there is no explicit when-to-use/when-not statement or pointer to add_watch or get_price_history for follow-up actions.

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