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

Annotations already cover read-only, idempotent, non-destructive, closed-world behavior, so the remaining burden is light. The description adds real value beyond them: it discloses the privacy guarantee ('Nikdy neprozradí, komu obsazená subdoména patří') and that suggestions come back with the answer, which an agent cannot infer from annotations.

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?

Three short sentences, front-loaded with the core question and followed by the return shape and the privacy caveat. Slightly wasteful since the return-value sentence partly duplicates the existing output schema, but nothing is padded.

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?

A single-parameter, read-only check with an output schema — the description covers the privacy behavior and suggestion output, which is the part not visible elsewhere. Only the pre-creation sequencing with shopzi_create_store is left implicit.

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% and the schema already explains the input, the `.shopzi.cz` suffix handling, and the length bounds. The description only restates the domain format, adding no new parameter-level meaning, so 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 and resource ('Ověří, jestli je subdoména ... volná') with the concrete format `nazev.shopzi.cz`, making it immediately distinguishable from siblings like shopzi_create_store or shopzi_store_creation_status. An agent can route to it without reading 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?

'pro nový obchod' implies this is a pre-creation availability check, but the description never names shopzi_create_store or states that this should be called before it, nor does it state what to do when the result is occupied. Usage is inferable but not explicit.

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