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

With no annotations provided, the description carries the full burden and does so well: it discloses the 250-ASIN cap, credential resolution (saved Keepa key vs shared scan key), a credit/quota side effect, a premium gating constraint, and the asynchronous job_id + polling model. These are exactly the behavioral traits an agent needs before invoking.

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?

Front-loaded with the action and mechanism, then constraints, keying, return value, and gating. Every sentence adds distinct information; no restatement of the tool name or filler.

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 single-parameter async start tool with no output schema and no annotations, the description covers the return value (job_id), the follow-up tool to call, quota/credential implications, scale limit, and premium gating. Nothing essential to correct invocation is missing.

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 0% and the single parameter (asins) is undocumented in the schema. The description compensates meaningfully by stating what each ASIN triggers and enforcing a 'Up to 250 ASINs' bound that the schema omits, though it does not specify expected format or error behavior for invalid ASINs.

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 (start) and resource (Reverse Source scan) and explains the mechanism concretely: for each ASIN, search Google Shopping for a cheaper source than Amazon — i.e. where to buy the product to flip it. An agent can distinguish this from siblings like start_wholesale_scan or get_reverse_source_jobs without opening any schema.

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?

Gives clear operational context: up to 250 ASINs, uses the saved Keepa key or else the shared scan key counting against daily credits, and directs the agent to poll get_reverse_source_status(job_id) for results. It does not name explicit alternatives or when-not-to-use conditions, so it falls short of a 5.

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