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 that the result includes companyId, which is useful, but says nothing about scope (all companies vs. filtered), pagination, or ordering. With annotations carrying the safety burden, this is adequate but not rich.

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 sentences, both front-loaded and purposeful: the first defines the resource and its identifier, the second ties it to the downstream tools that need it. 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?

With no output schema and no parameters, the description must convey what comes back, and it does (companies plus their companyId). A simple no-arg list tool does not need more, though a note on scope or whether all companies are returned would close the last gap.

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?

The tool takes zero parameters, so the baseline is 4. The description's mention of companyId refers to a returned field rather than an input, but it correctly signals that no input filtering is needed.

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?

Names a specific verb+resource ('Firmy uzivatele' – the user's companies) and states the key returned field (companyId). It does not explicitly distinguish itself from sibling list tools such as list_suppliers or list_documents, but the resource is unambiguous.

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?

The second sentence supplies real routing context: it tells the agent that the databox and VAT filing tools require companyId, which is exactly the value this tool yields. That is a clear conditional use case, though it stops short of an explicit 'use this tool when you need X' statement or naming the exact siblings (get_databox_status, generate_vat_filing).

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