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

The description goes well beyond the annotations by disclosing the per-row billing rate ($0.36), the 20-row cap (header excluded), that 4xx/5xx are not charged, and the semicolon-delimited response format. These operational details are not present in the annotations and are critical for cost-aware and correct invocation. No contradiction with annotations.

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 description is two sentences, front-loading the resource type first, then pricing, row limit, error charging, and response format. Every sentence adds distinct information with no redundancy, making it compact and easy to parse.

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 simple two-parameter tool with an output schema and complete annotations, the description covers all critical operational aspects: cost, row cap, error handling, and response format. It leaves no significant gaps for an agent to call the tool correctly; any remaining details like pagination are likely outside the tool's scope.

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 input schema has 100% description coverage for both parameters, with clear examples and allowed values for `target_type`. The description adds no parameter-specific meaning, but with full schema coverage, the baseline of 3 is appropriate; the schema fully explains the parameters.

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 the tool returns 'Individual backlink records pointing at a target (source, target, anchor)', which clearly identifies the resource and the specific granularity. The phrase 'individual' differentiates it from sibling tools like overview, anchors, and competitors. The tool name and title reinforce the purpose.

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?

The description implies this is for raw, row-level backlink data rather than aggregated summaries, but it does not explicitly state when to use this tool over alternatives or provide exclusion criteria. No alternatives are mentioned, so an agent must infer usage from the 'Individual' qualifier and the sibling list.

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