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. The description then adds genuine value by enumerating the response contents despite there being no output schema. It omits any statement about data latency, empty-result behavior, or limits on breakdown cardinality, which is why it is not 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?

A single sentence that front-loads the most important element (scan totals) and then lists the breakdown dimensions compactly. No filler, no restatement of the title.

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 does list the breakdown dimensions, which is the right instinct. However, it is silent on the time-window parameter, on result size/pagination, and on what an empty analytics response looks like, leaving the tool only minimally specified.

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 coverage is only 50%: qrId is documented in the schema (with a pointer to list_qr_codes/create_qr_code), but the `days` window has no schema description at all. The description mentions no time range, so an agent gets no guidance on what 7/30/90 mean or which is selected by the default of 30. It does not compensate for the coverage gap.

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 names the specific dataset returned: scan totals, a daily series, and country/city/device/OS/browser breakdowns. That lets an agent distinguish it from get_qr_code (metadata) and get_qr_code_image without opening schemas. It lacks an explicit verb and never names a sibling for contrast, so a 4 rather than a 5.

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?

The analytics framing implies when to reach for it (checking scan performance) but there is no explicit trigger, no prerequisite such as the QR code needing to exist or have scans, and no mention of alternatives like get_qr_code for metadata. Usage is inferable, not stated.

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