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

Annotations already cover safety (readOnlyHint=true, destructiveHint=false, openWorldHint=true, idempotentHint=false), and the description adds substantial further context: it takes 10-25 seconds, costs $0.05 USDC via x402, specifies the payment metadata field, and clarifies that invalid input or failed runs return an error and are not charged. It also summarizes the return payload, which is important given there is no output schema.

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 core purpose is front-loaded, but the description is an extremely long single sentence packed with many comma-separated clauses. The information is relevant and dense, yet the lack of structure or paragraphing makes it less scannable than ideal.

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?

Despite having no output schema, the description explains the return values in detail: 100-point score, crawlerAccess, agentReady checks and fixes, prioritized fixes, result_url, badge_url, and a ready-to-paste kit. It also covers runtime, payment, and error handling, making it complete for a complex, paid, read-only scan tool.

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?

There is only one parameter and schema coverage is 100%, so the schema already documents the url input adequately. The description does not add syntax or format details beyond the schema, and its mention of fetching the homepage slightly differs from the schema's 'Website or page URL' phrasing, so the 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?

The description opens with a specific verb and resource ('Deep AEO scan of a website') and then enumerates the exact checks performed, so an agent can tell precisely what the tool does. It does not explicitly distinguish itself from the sibling tool full_report, which prevents a 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?

The description explains what the scan does and notes runtime and cost, which are useful invocation details, but it gives no explicit when-to-use guidance or alternatives such as full_report or pricing. An agent must infer when this tool is preferable to its siblings.

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