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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint and destructiveHint, so the safety profile is covered. The description still adds genuine value by warning that seller descriptions in the result are untrusted provider text, a prompt-injection caveat not captured by any structured field.

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 short sentences with zero padding. The core action is front-loaded and the security caveat follows immediately.

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?

An output schema exists, so return-value documentation is not required. For a read-only, single-parameter tool, the description covers identification and the untrusted-content risk; it is only missing route-selection guidance relative to siblings.

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 description coverage is 0% for the single 'slug' parameter, so the description must compensate. 'By slug' clarifies that the parameter identifies a specific published storefront, but gives no format or resolution detail, leaving the parameter only partially explained.

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 states a specific verb pair ('read and validate') and resource ('published marketplace by slug'), which is more precise than the bare title. It does not explicitly contrast itself with siblings like voidpay_services or voidpay_status, so 4 rather than 5.

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?

There is no guidance on when to use this tool versus the sibling tools (checkout_link, services, status), nor any stated prerequisites or exclusions. Usage is only implied by the verb and the 'published' qualifier.

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