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

No annotations are provided, so the description carries the burden. 'Return validated...' signals a read operation and adds a data-quality trait, but it does not explain what 'validated' means, error behavior, or whether invalid entries are omitted. For a simple getter with an output schema, this is adequate but not richly transparent.

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 short sentences with no filler. The core behavior is front-loaded, and the usage guidance is packed efficiently.

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 combination of a 100%-covered schema, an output schema, and a concise description covers the essential calling context. The only notable gap is that it does not explicitly state whether exactly one parameter is required or what happens if both are supplied.

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%, so the baseline is 3. The description adds value by framing days and date as mutually exclusive choices ('Use days... or date...'), clarifying selection intent beyond the schema's per-parameter descriptions.

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 ('Return') and resource ('validated Bitcoin Stratigraphy day entries'), making the tool's function immediately clear. It also distinguishes the two access modes (days vs date) without ambiguity.

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 explicitly tells the agent when to use each parameter: 'Use days for the most recent N entries or date for one exact YYYY-MM-DD entry.' There are no sibling tools or exclusions to mention, so this clear context earns a 4.

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