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

Annotations already state readOnlyHint=true and destructiveHint=false, so the agent knows this only reads data. The description adds some behavioral depth (e.g., totals include recoverable revenue, paging via limit, sorting) but doesn't disclose details like whether results are cached, how the buy-box share is computed, or the exact definition of 'situation' beyond naming the categories. It does not contradict the annotations, and with annotations covering the safety profile, a 3 is appropriate.

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 detailed but front-loaded with the core purpose and uses concrete examples. It could be slightly shorter, but it earns its length by explaining the return fields and giving usage triggers in the same breath. No 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 listing tool with 10 parameters and no output schema, the description explains the main output fields (who wins, prices, gap, seller count, situation, suggested_action, target price) and the default sort. It doesn't fully specify pagination behavior beyond 'this tool pages' or the exact meaning of each situation/suggested_action, but it doesn't need to restate everything the schema already covers.

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 100%, so the schema already documents all 10 parameters. The description adds high-level meaning (e.g., what max_buybox_share_pct means and that limit defaults to 25), but doesn't add per-parameter meaning beyond what the schema provides. Baseline 3 is correct when the schema carries the heavy lifting.

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 clearly specifies a single operator, the ASINs where it is losing the buy-box, and the ranking by estimated 30-day revenue at risk. It also explicitly names the return fields and the four situation categories, making the tool's function 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 does exactly what the user wants: lists explicit natural-language triggers ('where is seller X losing the buy-box', 'X's buy-box leaks', 'which ASINs should X reprice', etc.) and even mentions that it is sortable by revenue-at-risk, price gap, buy-box share, or listing revenue.

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