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

Beyond annotations declaring the call safe/read-only, the description adds important behavioral context: the $0.30 billing per successful call, no charge for 4xx/5xx responses, and semicolon-delimited response format. This is exactly the kind of non-obvious behavior an agent needs before invoking.

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 with no filler: the core purpose and output fields come first, then cost/billing caveat, then response format. Every sentence earns its place and the most important operational detail (cost) is included without bloating.

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 single-argument read-only tool with rich annotations and an output schema, the description covers output contents, billing behavior, error-charge behavior, and response format. Nothing an agent needs to invoke it correctly 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 the single parameter target is already clearly documented with format and an example. The description adds no deeper parameter semantics, but the schema carries the full burden adequately, so baseline 3 is appropriate.

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 ('Return') and resource ('backlink profile summary for a root domain') and enumerates the exact fields returned. The description clearly distinguishes this from domain-overview or competitor tools in the sibling list, even without naming alternatives.

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 guidance on when to choose this tool over alternatives such as get_semrush_domain_overview or get_ahrefs_domain_rating. The description defines what the tool does but does not state usage conditions, exclusions, or preferred alternative scenarios.

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