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

With no annotations provided, the description carries the full burden. It transparently discloses the return payload: 'total scans, scans by day, device breakdown (mobile/tablet/desktop), and top 5 countries.' It also implies read-only behavior by context. It does not mention any side effects or error conditions, but for a read-only analytics query, this is adequate.

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?

The description is three concise sentences: purpose, usage trigger, and return summary. It is front-loaded with the main verb and resource, and every sentence adds value without fluff or redundancy.

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 simple query tool with two parameters and no output schema, the description provides complete context: what it does, when to use it, and what it returns. The schema covers parameter semantics, and the tool has no complex edge cases or side effects requiring further elaboration.

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 100%, so the baseline is 3. The description adds minimal meaning beyond the schema: it implies days from 'daily scan trends', but the schema already fully describes id and days parameters. There is no additional context like parameter relationships or format details.

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 clearly states it retrieves scan analytics for a specific QR code, with a specific verb ('Get') and resource ('scan analytics'). It distinguishes itself from siblings like quality_qr_get or quality_qr_list by detailing specific analytics metrics (total scans, daily trends, devices, countries), making the purpose unmistakable.

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 description explicitly states when to use the tool: 'when the user wants to know how many times a QR code has been scanned, see daily scan trends...' This provides clear context. However, it does not explicitly mention when not to use it or name alternative tools for non-analytics queries, so it misses the full when/when-not/alternatives criterion.

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