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

Annotations already mark this as read-only and non-destructive, and the description adds substantial behavioral nuance beyond that: mid-refresh data is stale/empty, orderStats only appears when order sync is enabled, isOverlimit triggers upgradeUrl, and the two refreshing flags indicate an in-progress export requiring a wait-and-poll pattern. This is exactly the kind of runtime behavior an agent needs to call the tool correctly.

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?

The description is long but every sentence earns its place: purpose and return fields first, then the wait/poll signal and the freshness caveat, then parameter provenance and tool routing. The most critical operational guidance is front-loaded after the return-value summary, and no sentence is 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?

There is no output schema, so the description fully documents the return object, including nested productStats and orderStats, plus the semantics of isOverlimit, upgradeUrl, and the two refreshing flags. It also explains limitations (stale data mid-refresh), parameter sourcing, and when to use sibling tools, leaving no gap an agent would need to guess to invoke or interpret results correctly.

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?

With 0% schema description coverage, the description must compensate, and it does: marketplace_id is sourced from list_marketplaces, and project_id is optional in single-project contexts but required otherwise, directing the agent to list_projects. It doesn't describe the integer values' meaning beyond provenance and optionality, but that is genuinely useful semantic information the schema does not convey.

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 opens with a specific verb and resource — 'Get the live run status of one marketplace' — and enumerates exactly what is returned (readiness, connection, product/order counts). It also explicitly contrasts itself with get_marketplace (configuration/mapping) and get_marketplace_report (error breakdown), so an agent can distinguish it from siblings without inspecting schemas.

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?

The description gives concrete polling guidance: after an export or submit, poll until both productsRefreshing and productsSubmitting are false before reading results. It also specifies when project_id is needed and instructs calling list_projects when project_id_required, and it names the alternatives for run progress vs. configuration vs. error details.

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