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

Goes far beyond the annotations: discloses that the tool performs no upload itself, that it returns per-file curl commands valid for ten minutes and scoped to one product, that re-sending corrects rather than duplicates (consistent with idempotentHint=true), that nothing is deleted (consistent with destructiveHint=false), and that an MCP_API_KEY bearer token plus a confirmation step are required.

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 blocking value and the multi-directory payoff are front-loaded, and the operational caveats follow in a sensible order. Slightly padded – 'IMPORTANT: this tool uploads nothing by itself and cannot' is largely restated by the next sentence about the remote server.

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, and the description compensates by explaining exactly what is returned (a curl command per file, ten-minute validity, product-scoped). Auth, confirmation, and idempotency semantics are all covered, so an agent can call this correctly without further context.

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%, so baseline is 3. The description adds constraints the schema does not carry: the 3-5 image count, PNG/JPG format, and 1280x720 minimum that directories demand, which gives the agent a way to validate inputs before calling.

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?

Names a specific verb and resource ('attach real product screenshots ... to one of your tracked products') and immediately ties it to the two sibling tools it feeds (check_submission_readiness, generate_submission_kit), so it is distinguishable from every other sibling in the list.

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?

States the triggering condition clearly: use this when readiness/kit output reports screenshots missing. It also rules out a whole class of misuse ('never fetches, generates, resizes or substitutes'). It stops short of naming an alternative tool for the cases where the agent has no local files, so it is not a full when/when-not/alternatives treatment.

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