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

Annotations already declare readOnlyHint=true, idempotentHint=true, openWorldHint=true, and destructiveHint=false, so the safety profile is covered. The description adds genuinely useful temporal context – the snapshot is taken 'for the moment when you make a request' and includes the last 12 months – but says nothing about cost, rate limits, or freshness lag typical of index endpoints.

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 tight sentences that front-load the core output (total backlinks, domains, pages) before the secondary 12-month stats. No filler or repetition 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?

An output schema exists, so return-value shape need not be described, and the no-param schema is trivially complete. The description covers the data scope and temporal snapshot well; only the routing question against sibling tools is unaddressed.

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?

The tool takes zero parameters, so the baseline is 4. There is nothing for the description to clarify and nothing to compensate for.

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 ('provide you with') and resource scope: total counts of backlinks, domains, and pages held in the database, plus 12-month stats. This is clearly an aggregate index/snapshot endpoint, distinguishing it from the many per-domain/per-page siblings, though it never names a sibling 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?

No when-to-use guidance is given. With ~30 sibling tools mixing index stats, live queries, and summary endpoints, the description never says when to call this index endpoint versus post_dataforseo_backlinks_summary_live or get_semrush_indexed_pages.

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