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

Annotations already declare readOnlyHint=true, openWorldHint=true, and destructiveHint=false, so the safety profile is covered. The description adds only 'free' (no cost) and the probe framing; it does not say what happens on failure, whether it makes live network calls to the target, or what the sample payloads contain. Modest added value over the 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?

One sentence, front-loaded with the tool's function, with no filler. It is efficient, though the marketing-flavored adjectives ('free', 'autonomous routers') are not strictly load-bearing.

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?

An output schema exists, so return values need not be explained, and annotations carry the safety profile. The remaining gap is routing context: nothing tells the agent when this diagnostic belongs in a workflow versus the substantive data tools. Adequate but with a clear usage hole.

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 single optional parameter (include_samples, default true) is fully documented in the schema. The description's phrase 'sample payload discovery' gestures at that toggle but adds no syntax or behavioral detail beyond the schema, so the baseline 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 names a concrete function ('uptime probe and sample payload discovery') and scopes it to MCP registries and autonomous routers, which is enough to separate it from unrelated siblings like arxiv_agent_papers or security_url_threat_check. However, 'sample payload discovery' is jargon that never resolves into a plain statement of what it returns or checks.

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?

There is no when-to-use guidance, no prerequisites, and no mention of alternatives. The agent must infer that this is a meta/health-check utility rather than a data-retrieval tool, which is left entirely to guesswork against 18 topically unrelated siblings.

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