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

No annotations are provided, so the description carries the burden of disclosing behavior. It does add the external source (satoshidata.ai) and indicates the data is 'current', which is useful context. It lacks details about freshness guarantees or potential network dependency, but for a simple read-only query this is adequate.

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 a single, front-loaded sentence with no filler or redundancy. Every word contributes to specifying the tool's purpose and data source.

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?

This is a very low-complexity tool with zero parameters and an output schema present. The description provides the core purpose and source, which is sufficient for a tool of this simplicity; return values are already documented by the output 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?

The input schema has zero parameters, so schema coverage is complete. With no parameters to describe, the baseline of 4 applies; the description adds no parameter-related content because none is needed.

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: returning current recommended Bitcoin fee estimates. It identifies both the action ('Return') and the resource ('fee estimates from satoshidata.ai'), making it easily distinguishable from the broader set of sibling tools.

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?

Usage is implied: use this tool when you need current recommended Bitcoin fee estimates. However, there is no explicit guidance on when this tool is preferred over alternatives like mempool_stats or onchain_stats, nor any exclusions or context.

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