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

With no annotations provided, the description carries the full burden of behavioral disclosure. It discloses that the tool is free to call, rate-limited (20 scan starts / 15 min shared across all agents), and provides status/limit information. It does not mention side effects (likely none), but for a read-only info tool, the transparency is strong. It does not contradict any 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?

The description is compact and front-loaded with the core purpose. The additional sentences about rate limits and alternatives are valuable but include lengthy URLs that slightly reduce readability. Still, every sentence contributes meaningful context, and the structure is logical.

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's simplicity (0 params, no output schema), the description fully covers what an agent needs: purpose, usage context, rate limits, and alternatives. It even addresses cost (free) and shared rate limits. The description is complete enough for the agent to decide when and how to invoke this 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?

The tool has zero parameters, so the baseline is 4. The description adds no parameter-specific semantics, but that is unnecessary. It does clarify the scope of the info returned, which implicitly describes the output rather than input parameters.

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's function: providing live chain tip, scanner reachability, and free-tier limits for Zcash UFVK scanning. It distinguishes itself from siblings by explicitly positioning itself as the starting point before scanning and by pointing to alternative endpoints for other use cases. The verb 'start here' and the listed data make the purpose unmistakable.

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 usage guidance: 'Start here before scanning' for quick checks of chain tip and limits. It also specifies when NOT to use it, directing users to private/historical for scheduled/bulk/latency-sensitive work or private/info for webhook-based notifications. This clears differentiates from sibling tools and alternative endpoints.

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