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

Annotations already establish readOnlyHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is covered. The description adds one genuinely useful behavioral caveat — 'orientacni' signals the calendar is indicative and not authoritative — but says nothing about the return format or how the window is applied.

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 short, front-loaded fragments with no filler: the scope and subject come first, the indicative caveat second. Nothing is wasted, though the fragments are terse enough to feel clipped.

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 simple read-only calendar with one optional parameter this is nearly adequate, but with no output schema the description should at least sketch what a deadline entry contains (dates, obligation labels, applicability). That return-shape gap keeps it at minimum viable.

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?

One optional parameter with 100% schema coverage (including its default of 60 days and 1-365 bounds), so the schema fully documents the input. The description adds no meaning beyond that, which is the expected baseline when coverage is complete.

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 names a specific resource (upcoming tax deadlines) and scopes it precisely to Czech sole traders and VAT payers, enumerating the obligation types (VAT, ZP/SP advances, income tax). This clearly separates it from siblings like generate_vat_filing or get_vat_summary, though it does not explicitly name an alternative.

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?

There is no statement of when to reach for this tool versus generate_vat_filing, list_vat_filings, or get_vat_summary. The word 'orientacni' implies it is informational rather than a filing action, but that inference is left to the agent.

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