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

Annotations already declare readOnly/idempotent/non-open-world, so the safety profile is covered. The description adds real value beyond that: facts arrive with official/primary sources and a verification date, and it discloses the specific misinformation it corrects (January 2027 not a pilot, no 50k CZK exemption, tax credit 'up to' 5,000 CZK).

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 topics, then corrections, then args/returns. The corrections paragraph is unusual but earns its place by flagging assertions the tool will make; slightly verbose overall but no clearly wasted sentence.

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 supplies the return shape (facts[{topic,title,text,sources[{label,url}]}], facts_updated), the topic enum, and the default format. Nothing essential to calling it correctly 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 coverage is 100% and the schema already documents both parameters and the enum values. The description's 'Omit topics to get all of them' and the args listing essentially restate the schema, adding little semantic detail beyond it, 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?

States a specific verb+resource ('Return short, sourced facts about EET 2.0') and its scope ('on chosen topics'), and the enumerated topics make it easy to distinguish from siblings like eet_get_guide or eet_list_misconceptions. An agent can tell what this does without opening the 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?

It gives one operational instruction ('Omit topics to get all of them') but never states when to prefer this over the sibling retrievers (eet_get_guide, eet_search_guides, eet_list_misconceptions). Usage is implied by the topic list rather than explained.

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