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

Annotations already cover the safety profile (readOnlyHint, destructiveHint: false, openWorldHint), so the bar is lower. The description nonetheless adds genuinely useful operational context: a 30-60 second latency expectation, an API-key requirement, and a free StartupHub.ai account prerequisite.

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 definition is compact and front-loads the core metric definition before latency and auth prerequisites. Every clause carries information; no 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 read-only tool with full schema coverage and annotations declaring safety, the description supplies what the structured fields cannot: latency, auth, and account prerequisites. Only the missing sibling routing against check_domain_rating keeps it from being complete.

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 the schema already documents both 'domain' and 'keyword' (including the default-from-homepage-title behavior). The description adds no parameter-level meaning beyond the schema, which is the baseline-3 case.

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 states a specific resource and metric: a 0-100 'effective' domain rating measuring realized visibility, positioned against Ahrefs Domain Rating. It is clear what the tool returns, but the differentiation from the near-identically named sibling check_domain_rating is only implied by 'set next to Ahrefs Domain Rating' 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?

There is no explicit when-to-use, when-not-to-use, or alternative routing, despite the sibling check_domain_rating being easily confused with this tool. The phrase 'set next to Ahrefs Domain Rating' hints at a complementary relationship but never tells the agent which of the two tools to pick or why.

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