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

No annotations are provided, so the description carries the full burden and does so: live fetch from Ceneo.pl, latency expectations (a few seconds, up to ~20s via an unblocker backend), and the important semantic that count:0 with a `note` is a success, not an error. It also warns that `lowestPrice` is a formatted string, not a number — a real gotcha for an agent.

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?

Front-loaded with purpose, then result shape, then the no-match rule — a sensible ordering. It is somewhat dense and repeats the ceneo_product_offers handoff twice ("use it with ceneo_product_offers" and "call ceneo_product_offers with a product `id`"), which is minor redundancy rather than waste.

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 two-parameter search tool with an output schema, the description covers everything an agent needs: input semantics, latency, the shape of the payload, the type of `lowestPrice`, and how to interpret a zero-result response. Nothing required to call it correctly or interpret its output 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% and both parameters (phrase, limit with default 24 / max 60) are documented in the schema. The description reinforces what `phrase` means by describing the result fields it drives, but adds no syntax or constraint detail beyond the schema, 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?

Opens with a specific verb and resource ("Search Ceneo.pl ... by phrase") and immediately states what the result contains (lowest price, shop count, Ceneo product id). It explicitly separates itself from ceneo_product_offers, so an agent can distinguish it from siblings without opening a schema.

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?

Clear routing guidance: use this for phrase search, then call ceneo_product_offers with the returned `id` for per-shop offers. It does not explain when to prefer ceneo_product (the third sibling) over this tool, so the when-not coverage is partial rather than complete.

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