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

Annotations already establish readOnly, idempotent, non-destructive and openWorld behavior, so the safety profile is covered. The description adds that results are paginated and that the underlying call is a POST to /api/account/scans, which is modest extra context, but the default-range sentence merely duplicates the start_date/end_date schema descriptions.

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?

Two short sentences, front-loaded with the action and scope, with no filler. The endpoint detail is of marginal value, but nothing is padded or buried.

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?

An output schema exists so return values need no explanation, and 100% parameter coverage means the only job left is orientation, which the scope and default-range statements provide. An agent can call it correctly, though it lacks guidance on paging limits and on the overlap with the by-date/by-region/by-device siblings.

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%, so all eight parameters (including the group_by enum and the conditional country requirement) are already documented, making the baseline of 3 appropriate. The description only echoes 'optional group_by' and the date default, adding no syntax or interaction detail beyond the schema.

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 (Fetch) and resource (paginated scan data) with an explicit scope qualifier, 'for the whole account', which implicitly separates it from get_project_scans and get_qrcode_scans in the sibling list. However, it never names those alternatives, so the differentiation is inferred rather than stated.

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?

'For the whole account' implies when this tool is preferable to the project- or qrcode-scoped scan tools, and the default 30-day window is given. There is no explicit when-to-use/when-not-to-use statement or mention of the many aggregation siblings (get_scans_by_date, get_scans_by_region, etc.) that overlap with this tool's group_by option.

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