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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so the safety profile is covered. The description goes further and discloses what actually comes back: three time windows with percentile spreads, price buckets, daily trend, category benchmark, and named anomaly flags, plus the `insufficient_data: true` degradation case. It does not mention history depth costs, data lag, or auth, which keeps it below a 5.

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?

Purpose is front-loaded in the first clause, followed by a compact pipe-delimited return-shape spec — dense but structured, with no filler sentences. Minor deduction for cryptic shorthand (d30/d90, p25/p75) that assumes familiarity rather than defining it.

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?

No output schema exists, so the description must document the response itself — and it does thoroughly, including window keys, bucket fields, and the sparse-data sentinel. What's missing is peripheral: whether history is per-product only, and how missing/unknown product_id is handled.

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?

There is a single required parameter (product_id) with 100% schema description coverage, so the schema already carries the meaning and the description adds nothing about the identifier format or expected source. Baseline 3 applies when the schema does the work and the prose is silent on parameters.

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 resource and scope: historical sale price AND volume for a product, with a stated rationale (detecting bottom-price dumping bait). This clearly separates it from transactional siblings like webaz_buy or webaz_place_order, though it never names its closest analytical sibling (webaz_verify_price) explicitly.

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?

Usage is only implied via the motivation clause 'helps agents avoid bottom-price dumping bait' — an agent can infer this is a pre-purchase sanity check. There is no explicit statement of when to call it versus webaz_verify_price or webaz_search, and no prerequisites or exclusions.

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