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

Annotations already cover read-only, idempotent, and non-destructive behavior. The description adds useful context that this is a snapshot and costs $0.01, but it does not explain payment challenge behavior or rate limits beyond what the schema provides.

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 short, front-loaded, and free of fluff. The endpoint fragment is a bit terse, but the overall size is appropriate for a simple read-only tool.

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?

The description lists the snapshot components and states the price, which is useful. However, with no output schema, it does not describe the return shape in detail, and it leaves payment-flow behavior to the schema.

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 both host and payment are already documented in the schema. The description mentions the host parameter in the endpoint path but adds no meaningful semantics beyond the schema.

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 resource scope: a DNS, TLS certificate, HTTP status, and latency snapshot. It is specific enough to distinguish a site-health check from sibling tools like check_security_headers or run_seo_audit, though it does not explicitly name 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?

It provides no when-to-use or when-not-to-use guidance and does not route the agent between this tool and related siblings. The endpoint notation and price are implementation details, not usage guidance.

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