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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description's one added behavior note is 'published', which usefully signals that unpublished listings are not returned, but it says nothing about not-found behavior or what fields come back.

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 nine-word sentence with the verb, cardinality, scope, and identifier all front-loaded. There is no filler and nothing to trim.

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 simple single-parameter read with no output schema, the description covers the essential lookup contract but omits the result shape and the not-found case, both of which the agent would otherwise have to discover empirically.

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% and the slug parameter already carries a pattern, length bounds, and description, so the schema does the heavy lifting. The description only restates that lookup is by slug, adding no format or resolution guidance beyond that.

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?

States a specific verb ('Get'), cardinality ('one'), and identifier ('by its slug'), which separates it from the plural search_listings and list_* siblings. The only wrinkle is that it calls the resource an 'agent wallet' while the tool and parameter are named 'listing', which leaves a small terminology ambiguity.

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?

No statement of when to use this instead of search_listings or the list_* tools. The slug-vs-filter distinction is only implied by the parameter, so an agent must infer the routing rule on its own.

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