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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is fully covered by structured data. The description's only added behavioral detail is 'published', implying unpublished records are not retrievable, which is genuinely useful but minimal. It says nothing about what happens when a slug does not match.

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 front-loaded sentence with the identifier constraint placed at the end where it belongs. Nothing is padded or 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 one-parameter read tool with complete annotations and no output schema, the description covers enough to invoke it correctly. It is only slightly thin on what 'published' excludes and what a miss returns, neither of which is critical.

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%: the single 'slug' parameter has a type, pattern, length bounds and description already. The description's 'by its slug' merely restates the schema and adds no format or sourcing guidance beyond it, so baseline 3 applies.

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) and resource (one published auction house or platform) scoped by identifier (slug). The singular 'one' implicitly distinguishes it from the plural list_* and search_listings siblings, though it never names them. The slight mismatch between the tool name (get_listing) and the returned entity (auction house/platform) is at least clarified by the description.

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: the 'by its slug' phrasing signals you must already have a slug, which suggests this is a lookup after discovery via search_listings, but no alternative is named and no when-not condition is given. No prerequisites or error/not-found behavior are described.

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