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

Annotations already declare readOnly, idempotent and non-destructive, so safety is covered. The description adds real value beyond them: relative cost ('heaviest read'), the Austria-only limitation with the German-id error behavior, and the unknown-code passthrough. It stops short of describing size/pagination of the payload, but that is a minor gap.

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?

Front-loads purpose, scope and the cost warning, then a labeled Parameters block. Slightly long with the code-formatting and lineage phrasing, but every sentence earns its place; 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?

An output schema exists, so return values need not be enumerated, yet the description still helpfully notes the payload includes 'country', the prefixed company_id, unknown-code passthrough and covered filing years. Nothing an agent needs to call this correctly is missing.

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 coverage is 0%, so the description must carry the parameter — and it does, giving the id format 'AT:{fnr}', noting a bare FNR is accepted, and stating the Austria-only constraint. This fully compensates for the empty schema.

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 ('complete multi-year record for ONE company') with explicit scope ('every balance-sheet and P&L position's full per-year history'). It directly names the sibling it is not — get_company_details for a normal profile — so an agent can separate the heavy read from the light one.

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?

Explicitly routes the agent: 'The heaviest read - use get_company_details for a normal profile', plus the hard constraint that only Austria works today and a German id returns an error. When-to-use and when-not-to-use are both present.

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