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

With no annotations, the description carries the disclosure burden; it adds useful context by naming the data source (Compera Ränteindex) and freshness ('dagsfärskt'). It does not specify response format or update behavior, but these omissions are modest for a no-parameter lookup.

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?

A single compact sentence that front-loads the main result and appends the source and ranking detail. No filler or redundancy.

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 zero-parameter tool, the description names the metric, geography, freshness, source, and the top-list component. It could mention ordering or caveats, but nothing essential is missing for invoking it correctly.

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?

There are no parameters, so the schema has nothing to document. The baseline is 4, and the description adds relevant scoping context by specifying geography ('i Sverige') and output granularity ('per långivare').

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 identifies a specific resource (lowest effective private loan rates in Sweden) and adds source/freshness context ('dagsfärskt Compera Ränteindex') plus a top list per lender. It lacks an explicit action verb but is clear and distinguishable from sibling comparison tools.

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 guidance on when to use this tool versus siblings like compare_category or product_offers. The zero-parameter signature makes it self-contained, but the description leaves selection criteria implicit.

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