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

Annotations already declare readOnlyHint and openWorldHint, so the safety profile is covered. The description adds material behavioral context: the storefront is public, the payload shape mirrors chrono24_search, and the record is a single entity. It omits pagination behavior for the inventory list and any rate-limit/auth notes, so it falls short of a 5.

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?

Two sentences, front-loaded with what the tool returns and followed by the parameter provenance constraint. Every clause carries information; nothing is redundant.

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 single-param read tool with an output schema, the description supplies the payload summary, the entity scope, and the slug-acquisition path. An agent has everything needed to invoke it correctly without further inference.

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 burden, and it does: it explains that Slug identifies a dealer/seller, states the two concrete sources for obtaining it (search or listing seller links), and notes slugs are not a closed enumerable set. That is genuinely additive over a bare 'Slug: string'.

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 names a specific resource ('One Chrono24 dealer/seller's public storefront') and enumerates exactly what it returns: business description, trust badge, rating/review count, watches-sold count, and current inventory. It is cleanly separable from siblings like chrono24_search (list) and chrono24_dealer_reviews (reviews) without opening any schema.

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?

It explicitly tells the agent where the required slug comes from ('found in a chrono24_search or chrono24_listing result's seller link') and rules out a non-existent alternative ('there is no separate dealer-discovery endpoint'), which is exactly the missing context an agent would otherwise guess at.

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