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

Beyond the readOnlyHint/destructiveHint annotations, the description discloses the dependency on prior feed generation, the async export nature, the two error groups (dataCheckErrors pre-submission vs channelErrors post-submission), and the semantics of level/count/fixSuggestions. No contradictions with the annotations.

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?

Dense but purposeful; the length is justified by the absence of an output schema and the nested return structure. It front-loads the core purpose, then methodically explains return shape, field semantics, prerequisites, and sibling routing. No wasted or redundant sentences.

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 tool with 2 parameters, no output schema, and nested return fields, the description covers everything needed: exact return JSON, field meanings, when data exists, how to poll, and how to act on fixSuggestions. An agent can invoke it correctly without guessing.

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%, but the description fully compensates: 'marketplace_id is the id from list_marketplaces' and 'project_id is OPTIONAL (inferred for a single-project customer; project_id_required otherwise — then call list_projects)' explains both parameters' origin, optionality, and conditional requirement.

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 action and object: 'Get the validation report for one marketplace: the aggregated errors and warnings that block or degrade its listing, with fix suggestions.' It explicitly differentiates itself from the sibling: 'for a single product's report use get_marketplace_item_report', making its marketplace-wide scope unmistakable.

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?

It provides direct routing to the alternative tool for single-product reports, and states when the report is meaningful: 'Data-check errors exist only after a generation has run — finish the wizard, or repair_marketplace to (re)generate; export is async, so poll marketplace_status until productsRefreshing AND productsSubmitting are false'. It also tells where to get marketplace_id and when to call list_projects for project_id.

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