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

Annotations already declare readOnly, non-destructive and open-world behavior, so safety is covered. The description adds meaningful disclosure beyond that: only public listing details are returned, with hidden listings and private notes excluded — exactly the filtering behavior an agent must know before quoting results to a buyer.

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 the use case and followed by the scope restriction. No filler, no repetition of schema field text.

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 an output schema present, the description need not explain return values, and it covers lookup modes and visibility filtering. The only gap is what happens when a listing exists but is hidden — whether that yields an error or a not-found — which matters for an agent's error handling.

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%, so the baseline is 3, but the description adds the relationship the schema leaves implicit: id is one lookup path and sellerSlug plus listingSlug is the alternative, not cumulative filters. That disambiguation genuinely helps an agent decide which params to populate.

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 verb and resource ('get one public listing') and explicitly scopes the result to public data, which separates it from siblings like get_listing (non-public) and list_public_listings/search_public_listings (plural). An agent can pick this tool without opening the 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 gives a clear trigger ('when a buyer asks for one public listing') and the two acceptable lookup shapes. It does not name the plural siblings as alternatives for browsing, but the singular scope is stated clearly enough to imply the boundary.

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