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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds useful behavioral details beyond those annotations: only confirmed reservations are included, the numbers match a specific UI panel, and results are scoped to one apartment. This helps the agent understand what the tool actually returns and what assumptions it makes.

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?

The description is two sentences with no filler. The main output and scope are front-loaded, and the second sentence justifies the required parameter without redundancy. Every clause adds value, and the length is appropriate for the tool's complexity.

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 a high-coverage schema, read-only annotations, and an output schema available, the description covers everything an agent needs to invoke this tool correctly: what it returns, its scope, its data source (confirmed reservations), and the mandatory parameter. There are no missing prerequisites or ambiguous behaviors that would prevent a correct call.

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%, so the schema already documents both parameters, including that apartment_id is required and comes from list_apartments. The description adds a useful rationale for apartment_id — different nightly rates make cross-apartment summing meaningless — but it does not add new syntax or format details for months. The schema carries the main parameter documentation burden, so a baseline 3 is appropriate.

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 states exactly what the tool provides: monthly occupancy and revenue for one apartment, using only confirmed reservations. It also anchors to the panel's Statystyki page, making it easy to distinguish from sibling tools like get_pricing or get_reservation. It lacks an explicit verb like 'returns' or 'retrieves,' but the noun phrase is specific enough to identify the purpose.

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 description gives clear context: it is for one apartment and uses the same numbers as the Statystyki panel, which tells an agent when this tool matches the user's request. It also explains why apartment_id is required and why multi-apartment aggregation is invalid, effectively warning against calling it for portfolio-level stats. It does not explicitly name alternative tools or say 'do not use for X,' but the context is clear.

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