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

Annotations already declare readOnly, idempotent and non-destructive, so safety is covered. The description adds real behavioral context beyond that: each fact carries value, unit, attribution (with 'Confirmed' defined as a first-party statement) and source page, plus the pagination threshold and page size. It stops short of describing ordering, error cases, or what an unknown topic returns.

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 what the tool returns, then filtering, then pagination — a logical order. The long topic enumeration is information-dense and earns its place by telling the agent what can be filtered, though the sentence is heavy and could be tightened.

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?

With no output schema, the description carries the return-value burden and does so well: it describes the fact tuple (value, unit, attribution, source page) and the paging model. The main gap is the absence of any statement distinguishing it from get_product_facts, which matters given how many sibling fact tools exist.

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 all four parameters (product_slug, topic, limit, offset) are already documented in the schema. The description reinforces topic filtering with examples and ties offset/limit to the pagination rule, but adds no syntax, format, or constraint detail the schema lacks — the baseline 3 for full coverage 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 — 'every individual fact for one product' — and enumerates the topic groupings, so the agent knows exactly what content comes back. It does not, however, differentiate itself from the closely named sibling get_product_facts (or get_ownership_facts), leaving the agent to guess which fact tool to pick.

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?

It explains how to use the topic filter ('narrows the list') and when pagination kicks in (>20 facts, use offset/limit), which is useful operational guidance. But there is no explicit when-to-use-this-vs-alternatives statement, and the near-identical sibling get_product_facts is never mentioned or excluded.

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