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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint. The description adds important behavioral context: filter values must use German names, detail_url must be displayed as clickable, and vehicle_id must never be shown. These are critical usage rules not captured in annotations or schema.

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 three sentences, front-loaded with the core purpose. Each sentence serves a distinct role: stating purpose, noting German filter names, and giving critical output handling instructions. No wasted words or repetition of schema details.

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?

Despite no output schema, the description summarizes return content (vehicles with prices, images, links). It also anticipates user pitfalls (German names, internal ID). It could mention default sorting or limit, but those are in schema, making the description sufficient for agent navigation.

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 100% with each parameter described. The description adds a general rule that all filter values use German names, which applies to multiple parameters like fuels, colors, and cartypes, but the schema already mentions 'in German' for several. Thus the description adds some value but does not significantly elevate beyond the 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?

The description clearly states the tool's purpose: 'Search available cars on FINN with filters.' It uses a specific verb and resource, and the mention of 'available cars' plus returning 'prices, images, and links' distinguishes it from sibling tools like get_vehicle_details (specific vehicle details) and get_available_filters (filter options).

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 provides implicit usage guidance by stating that vehicle_id is for get_vehicle_details, linking search to a sibling tool. It also instructs users to always show detail_url as clickable links. However, it does not explicitly say when to use this tool over others or mention get_available_filters for valid filter values.

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