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

Annotations already establish readOnly, idempotent, non-destructive, non-open-world behavior, so the safety profile is covered. The description contributes genuinely new context beyond that: it discloses what the corpus covers (the exact 19 topics), that entries are verified and date-stamped, and that each fact carries a source citation, which tells the agent how authoritative and checkable results will be. It does not state result caps or behavior when no argument is supplied, which keeps it below 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?

The lead sentence is well front-loaded, but the remainder is one very long sentence that packs 19 topics into a dense run-on, which is hard to scan and partially duplicates the schema enum. The topic glosses are worth keeping, but the structure would benefit from breaking them into a list or trimming the parenthetical sub-items that the schema already implies.

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?

An output schema exists, so return-value explanation is not required, and annotations cover safety. The notable gap is that all three parameters are optional and the description never says what a no-argument call returns or whether omitting topic/query is a valid way to browse the whole guide. Given the breadth of the tool, that behavioral edge case should be stated.

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 a 3 would be the floor; the description exceeds that by glossing what each enum value actually contains (e.g. intl-tax covers VAT registration, reverse charge, OSS, permanent establishment, transfer pricing, Estonian CIT, IP Box; exit covers suspension, conversion, liquidation). This lets an agent choose a topic without guessing from the slug. The lang and query parameters are left to the schema, which is acceptable given full coverage.

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 opening sentence states a specific resource and scope: verified legal facts about doing business in Poland, each tied to an act, article, official link and verification date. The 19-topic enumeration makes it unmistakably a reference/knowledge-base lookup rather than a calculator or lookup like get_tax_rulings or plan_business_entry. It stops short of naming a sibling it should not be used instead of, so it is clear but not fully differentiated.

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 closing sentence, 'Pass a topic, a query, or both,' implies the calling pattern, but the 'both' case has no explanation of how topic and query interact (filter? combine? intersect?). No exclusion guidance tells the agent when to prefer get_tax_rulings, get_legal_limits, get_business_glossary or plan_business_entry instead. Usage is inferable but not stated.

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