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 safe read-only profile is covered structurally. The description adds useful content scope (breakdown by rate, input vs output), but says nothing about aggregation level, period semantics, or what happens when month/quarter are omitted. No contradiction with 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?

Two dense sentences, zero filler: the purpose and scope come first, then the disambiguating clause. Nothing is repeated from the title or 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?

For a read-only summary with no output schema, the description conveys what the summary contains but not its granularity (per-rate lines? per-month?), nor the required year plus optional month/quarter interaction. With annotations covering safety and a partly documented schema, this is adequate but leaves small gaps.

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 67%: year and month carry descriptions (month even notes the quarter/month exclusivity), and quarter is a self-explanatory enum. The description itself adds no parameter meaning beyond the schema, so the baseline of 3 is appropriate for medium-to-high coverage.

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 (VAT summary for a period) and enumerates its contents: bases and tax by rate, input and output. It even disambiguates from the sibling generate_vat_filing by noting it is the basis for the return, not the return itself, though it never names that sibling explicitly.

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?

"Podklad pro priznani, ne priznani samotne" clearly routes the agent: use this for supporting VAT figures, and the actual filing is a different operation. It implies the alternative without naming a specific tool or listing exclusions, so it stops short of a 5.

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