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

No annotations are provided, so the description carries the transparency burden. It discloses that heights are read live from own nodes, that schedules are protocol constants, and flags the DOGE flat-subsidy exception. It doesn't explicitly say 'read-only', but 'read live' and the nature of the data imply no side effects.

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?

Three sentences, front-loaded with the main purpose and output fields, followed by use case and operational notes. Every sentence adds unique value; there is no filler.

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 zero-parameter read-only tool with no output schema, the description covers the essential ground: output fields, live data source, protocol constants, and the DOGE edge case. An agent has enough to decide when to call it and what to expect.

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 and the schema confirms an empty object. With no parameters to document, the description doesn't need to add parameter semantics; the baseline of 4 applies. The 'every chain' phrasing clarifies the result scope.

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: a halving countdown for every chain, with a list of returned fields (height, next halving height, blocks remaining, ETA, rewards). It is clearly distinct from sibling status/intel tools, though it lacks an explicit verb like 'gets' or 'returns'.

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 provides an explicit 'When to use' section: when an agent needs a precise schedule anchor for emissions, mining economics, or long-horizon planning. It gives clear context but does not name alternatives or exclusions, so it stops short of a 5.

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