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

Annotations already mark this as read-only, idempotent, non-destructive, and open-world. The description adds meaningful behavioral context by specifying what data is returned, notably the 'last synced from MSB' timestamp, which signals freshness and dynamic data. No hidden side effects or safety concerns remain undisclosed.

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?

One compact sentence that front-loads the operation and scope, then adds three concrete data points. Every clause earns its place; there is no filler or repetition of the schema or annotations.

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 parameters, a complete output schema, and safety profile fully covered by annotations, the description provides all needed context. It even addresses dataset freshness, and the sibling list confirms the tool's niche as national aggregate stats.

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 has zero parameters, so there is no parameter behavior the description must explain. Baseline for zero-parameter tools is 4, and the description appropriately focuses on the output rather than parameter semantics.

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 uses a specific verb ('Get') and resource ('national statistics for Sweden's civil-defence shelters'), and enumerates the exact returned values: total registered shelters, total capacity, and last sync time. This clearly distinguishes it from sibling tools like get_shelter or search_shelters, which target individual shelters or searches.

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 'national statistics' wording makes it clear this is for aggregate overview rather than individual shelter lookup, providing usable context alongside the sibling tool names. It does not explicitly state when not to use it or name an alternative, but the scope is self-evident enough for correct selection.

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