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

Annotations already cover the safety profile (readOnly, idempotent, closed-world), and the description adds genuinely new behavioral context: the rulebook is paraphrased, not quoted, which matters for how the agent presents results. It doesn't describe matching breadth (e.g., multiple matches, empty results), so not 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?

Two tight sentences: what it returns first, then how to use it. The paraphrase disclaimer is well placed at the end. No filler.

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?

Output schema exists so return values needn't be explained, and the description still summarizes them and flags the paraphrase caveat. What's missing is behavior on ambiguous or zero-match queries, a minor gap for a simple single-parameter lookup.

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 query parameter's description already lists all the accepted forms (rule id, § number, word) with examples, so the description adds nothing beyond the schema here. Baseline 3 is appropriate.

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 (explain) and resource (orthography rules / Slovenski pravopis 2001), and names what is returned: rule, § number, paraphrase, reliability. It also explicitly links to the sibling check_orthography, distinguishing it from the other siblings.

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 justify a correction to the user" gives a clear use context, effectively positioning it as the follow-up to check_orthography. It does not state exclusions (e.g., don't use it to perform checks), so a 4 rather than 5.

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