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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is covered without the description. The description adds a meaningful behavioral bound — the series is capped at the last 100 scans and is chronological — which the annotations do not express. It says nothing about pagination or how missing scans are handled.

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?

One dense, front-loaded sentence that leads with the scope (score-over-time series for one product, last 100 scans, chronological) and then lists the returned metrics. The metric enumeration is long but every item carries information; no filler or redundant restatement of the tool name.

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 no output schema, the description carries the burden of explaining return values, and it does so by enumerating the metric families plus per-run source and timestamp. Given a one-parameter tool with full schema coverage and read-only annotations, little else an agent needs in order to call it correctly 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 description coverage is 100% and the single productKey parameter is documented in the schema as referencing list_products. The description reinforces that the series is scoped to 'one product' but adds no format or syntax detail beyond the schema, so the baseline of 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?

The description gives a specific verb+resource: a score-over-time series of the last 100 scans for one product, and enumerates the metrics returned (performance, AEO, CRO, SEO crawl, scorecards, CrUX, openRank, issue counts). It is clearly distinguishable from siblings like get_product or get_site_report, though it never names an alternative 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 implied by the phrase 'score-over-time series for one product', which suggests this is the tool for tracking trends over time rather than a current-state snapshot. There is no explicit when-to-use/when-not guidance or pointer to a sibling such as get_product for current values, so the agent must infer the distinction.

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