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

Annotations already declare readOnlyHint=false and destructiveHint=false, so the safety profile is covered. The description adds a genuinely non-obvious behavioral trait — that reports are cumulative and several are needed to remove a listing — which no annotation conveys. It stops short of saying whether the report is visible to the seller or what the caller gets back.

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?

Two sentences, no filler, with the action and the reason list front-loaded and the outcome clause second. Every sentence carries information an agent needs.

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?

With an output schema present and full parameter coverage, the description does not need to explain return values. It covers purpose and the takedown consequence, but leaves the post-call state (e.g., confirmation, whether the report is anonymous) unstated for a mutation tool.

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 all five parameters, including note length limits and the idempotency_key retry semantics, are already documented in the schema. The description only echoes the reason categories, adding nothing about format or usage of owner_key/listing_id, so baseline 3 applies.

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?

Starts with a clear verb+resource ("Report a listing") and enumerates the violation categories, which map directly onto the reason enum. It is distinguishable from siblings like market_block or market_search, though it never explicitly contrasts itself with them.

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?

"Report a listing that breaks the rules" implies the trigger condition, and "Several reports take it down" implies the effect. However, there is no guidance on when to prefer this over market_block, market_withdraw_listing, or contacting the seller via market_ask_seller.

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