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

Annotations already carry destructiveHint=true and idempotentHint=false, so the safety profile is covered. The description adds genuine value beyond annotations: the 200-per-request limit, the seller-ownership filter, per-product validation, and the fact that it is a thin adapter over two specific endpoints, which tells the agent the behavior mirrors those APIs. It does not disclose partial-failure semantics or what happens when some products fail validation, a gap for a destructive bulk operation.

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?

Roughly 60 words across three sentences, with the core purpose front-loaded in sentence one, mechanics in sentence two, and mode selection guidance in sentence three. Every sentence earns its place; no filler or repetition of the title. Minor deduction only because the adapter/endpoint detail in sentence two is somewhat implementation-specific, though still useful.

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 destructive bulk mutation with no output schema, the definition covers invocation well (what, scope, cap, modes, validation) but omits the response shape and partial-failure behavior — an agent cannot know whether a bulk call is all-or-nothing or per-item, nor what the return payload reports. These are material gaps given destructiveHint=true and the absence of an output schema.

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% — mode, value, and product_ids all carry descriptive text including the mode/value pairing and bounds. The description's third sentence reinforces the mode-to-value mapping ('price_set (value=USD)', 'moq_set (value=integer units)') but adds nothing the schema does not already state. Baseline 3 is appropriate since the schema carries the load and the description only confirms it.

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 first sentence names a specific verb ('Bulk update'), a concrete resource ('product listings'), and exact fields (prices or minimum order quantities), plus the 200-listing ceiling and owner scope ('calling seller's'). It is immediately distinguishable from every sibling: none of bulk_export_orders, bulk_mark_shipped, or create_listing cover price/MOQ mass mutation.

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?

Clear context is established: the operation applies only to the calling seller's own listings, caps at 200 per request, and reuses the same ownership filter and per-product validation as the underlying endpoints. The mode descriptions effectively tell the agent when each call form is appropriate. It stops short of explicitly naming alternatives or stating when not to use this tool, so no exclusions are given.

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