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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds one piece of behavioral value – that the payload includes a per-rate VAT breakdown – which matters because there is no output schema, but it says nothing about missing-document behavior, permission needs, or response shape otherwise.

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?

One compact sentence with the resource up front and the payoff (VAT breakdown) trailing. Nothing is wasted, and it is well matched to the complexity of a single-parameter getter.

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?

For a read-only lookup with full schema coverage and annotations, the description covers what the tool fetches and what the payload contains (VAT breakdown), which compensates for the absent output schema. It is nearly complete, missing only edge-case or error context.

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 single id parameter is documented in the schema as coming from list_documents. The description adds no further parameter semantics, so the baseline of 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 ("detail jednoho dokladu" = detail of a single document) and adds the return scope (VAT breakdown by rate), so the agent can distinguish it from list_documents. It stops short of explicitly naming the sibling it differs from, but the singular-vs-list distinction is clear from the description and 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?

Usage is only implied: the singular "jednoho dokladu" and the required id parameter signal this is the lookup-by-id path after list_documents. There is no explicit when-to-use/when-not statement or named alternative, leaving the agent to infer routing.

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