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

With no annotations, the description carries the full behavioral burden, and it does disclose a real constraint: an authenticated API key on the Developer plan. However, it omits return shape, whether results are paginated, and any rate-limit or freshness behavior, leaving meaningful gaps for a read tool.

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?

Three short sentences, front-loaded with the core purpose and ending with the auth prerequisite. Nothing is padded, though the auth note could have been folded more tightly into the first sentence.

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?

Purpose, filtering, and auth requirements are covered, but with no output schema the description gives no indication of what analytics data is returned (metrics, aggregation grain, shape). For a metrics-returning read tool this is a notable omission.

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 both qrCodeId and timeRange are already fully documented in the schema, including the '30d' default. The description restates the qrCodeId filtering but adds no syntax or semantics beyond the schema, so the baseline 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?

States a specific verb and resource ('Get scan analytics') and scopes it to 'the authenticated user's QR codes'. This is clearly distinguishable from the sibling tools generate_qr_code and list_qr_codes, though it never names them 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?

The description implies usage through the optional-filter phrasing, but it never states when to reach for this tool versus the siblings or what conditions warrant a filtered vs. account-wide query. Usage is inferred rather than guided.

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