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

Annotations already declare readOnly, idempotent, closed-world, non-destructive, so the safety profile is covered. The description adds material behavioral context beyond that: results are sourced, dated with an "as of", and contain a clearly labelled opinion, which tells the agent how much trust to place in each field.

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 first sentence is dense but front-loads what the tool returns and its provenance; the second earns its place as the usage trigger. The Args/Returns block is compact and scannable, with only minor redundancy against the schema.

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?

There is no output schema, and the description compensates by enumerating the returned fields (id, question, claim, truth, comment, as_of, sources, url, page_url). Combined with the read-only annotations and 100% schema coverage, an agent has everything needed to call it, though pagination or result-count behavior is 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 coverage is 100% with only two parameters, so the schema already documents both, including examples and the enum default. The description restates the query examples and the format options without adding syntax or matching semantics beyond what the schema provides — 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?

The description states a specific verb and resource — returning claims about EET 2.0 that contradict the adopted law or official Finanční správa information — and characterizes the source domain (media, commercial websites). That precision separates it from siblings like eet_get_facts or eet_get_guide without opening either 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?

"Use it to fact-check a claim before answering" gives a clear triggering condition. It does not name or exclude a specific sibling (e.g. eet_get_facts) as the alternative when the user wants neutral facts rather than debunked claims, so it stops short of full routing guidance.

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