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

With no annotations, the description carries full burden. It discloses that a live crawler runs, lists the exact 7 signals probed, describes the return format (score and breakdown), and clarifies it has no side-effects on submissions. This goes well beyond what structured fields provide.

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?

Two sentences, no redundancy. The first sentence front-loads purpose and mechanism; the second adds usage context and differentiates from a sibling. Every clause contributes value.

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-parameter tool with no output schema, the description is complete: it explains what the tool does, what it probes, what it returns, when to use it, and how it differs from alternatives. No gaps remain for an agent to invoke and interpret results correctly.

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 url parameter description is detailed (full URL vs bare domain, homepage works best, probes relative paths). The tool description itself adds no additional parameter semantics beyond that, so the baseline of 3 applies.

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 uses a specific verb 'check' with a clear resource 'any URL' and states the exact purpose: agentic-readiness. It enumerates the seven signals probed and the 0-100 score output, which fully distinguishes it from sibling tools like submit_site or verify_mcp.

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?

Explicitly states when to use: 'Use before calling an unfamiliar API to confirm it's agent-usable.' It also contrasts with submit_site, noting this tool is re-runnable without the submissions-table side-effect, making the appropriate alternative choice obvious.

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