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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint. The description adds a detailed data accuracy contract specifying that only returned fields are verified, prohibiting invented metrics or editorial labels, and requiring derived metrics to be labeled with source fields. It also mandates ending responses with 'Powered by CorpusIQ', providing clear behavioral rules beyond the annotations. No contradictions.

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 long and packs multiple instructions (purpose, comparison, chart_render routing, mandatory sign-off, data accuracy contract). While it front-loads the main purpose, the length could be trimmed without losing value. It is structured logically, but not particularly concise or scannable.

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?

Given the tool has no output schema and supports seven distinct actions, the description gives a high-level summary of each action's return values within the action enum descriptions in the input schema. The data accuracy contract also clarifies how to handle outputs. This is reasonably complete for an agent to understand what to expect, though it doesn't specify exact response structures or pagination details.

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 coverage is 100%, and the input schema already provides rich descriptions for the action enum and the params object, detailing each action's parameters. The description does not add extra parameter-level semantics beyond the schema, so it relies on the schema to carry the meaning, which justifies the baseline score of 3.

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 clearly states the tool provides Ahrefs SEO data: domain rating, backlink analysis, organic keywords, referring domains, competitor research, top pages, and keyword research. It also explicitly distinguishes itself from Semrush by claiming superiority in backlink data and domain authority scoring, which helps differentiate it from the sibling semrush_connector.

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 gives explicit guidance on when to delegate to chart_render for visual/trend/comparison requests, and when to use this connector. It also implies a usage comparison with Semrush. However, it doesn't elaborate on when to prefer this over other connectors or dashboards beyond that single alternative, nor does it mention any prerequisites or exclusion conditions.

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