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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds one genuinely useful behavioral detail — 'live' implies non-live/unpublished listings are not returned — but says nothing about error behavior for a missing or unpublished slug.

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 short sentence, front-loaded with verb and resource, with zero filler. Nothing needs trimming and nothing important is buried.

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 one-parameter read tool with annotations covering safety and a fully documented schema, the description is nearly sufficient. The only gap is the not-found / not-live case, which for a 'live listing' lookup an agent might reasonably want spelled out.

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 the single slug parameter fully described and even sourced ('e.g. from search_listings'). The description adds no format or syntax detail beyond the schema, so the baseline 3 for a fully documented schema is appropriate.

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 (get) and resource (one live listing) with a clear retrieval scope, so an agent immediately understands this is a single-item fetch rather than a search. It does not explicitly contrast itself with sibling search_listings, though 'one ... by its slug' implicitly separates it.

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?

Usage is only implied: 'by its slug' tells the agent a slug is required, and the schema note 'e.g. from search_listings' hints at the workflow, but that guidance lives in the schema, not the description. There is no statement of when to use this versus search_listings or what happens if the listing is not live.

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