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

Annotations already declare readOnlyHint, openWorldHint, non-destructive, and non-idempotent, so safety is covered. The description adds genuinely new behavior: results are ranked by citation count, represent sources engines already cite/trust, and the scan prerequisite. No return-format detail, but that is a minor gap against the annotation coverage.

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 sentences, front-loaded with the core action and resource. The middle sentence ('highest-value backlink targets') is value framing rather than operational detail, which is slightly promotional, but the prerequisite lands cleanly at the end. Overall tight.

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 read-only listing tool with no output schema, the description conveys what is returned (domains ranked by citation count) and the precondition for calling it. Parameters are fully covered by the schema. A note on pagination or output shape would push it higher, but nothing needed for correct invocation is missing.

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%, and all four parameters (days, limit, detail, site_id) are documented in the schema with defaults and an enum-like verbosity value. The description adds no syntax or format detail 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: lists external domains that AI engines cite in the site's space, ranked by citation count. This is clearly distinguishable in concept from get_visibility_results and suggest_sources. It stops short of explicitly naming a sibling to disambiguate, so it lands at 4 rather than 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?

Gives a real usage condition: 'Requires at least one completed visibility scan,' which tells the agent when this tool will fail. It also frames the value (backlink targets). It does not name an alternative (e.g., run_visibility_scan first, or suggest_sources for a different purpose), so it is clear context without explicit exclusions.

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