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

Beyond the readOnlyHint annotation, the description explicitly adds 'No auth needed' and 'READ-ONLY: this call changes nothing and can be repeated safely,' disclosing authentication requirements and idempotency. It also clarifies the scope of what is read. It does not mention output format or potential rate limits, but for a no-parameter read-only call this is solid coverage.

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 two sentences with no wasted words. The first sentence front-loads the core function and resource; the second efficiently covers authentication and safety. Every sentence adds value.

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, the description covers what it does, the data source, authentication, and safety. The absence of an output schema means the return shape is not documented, but 'Merkle tree heads' strongly implies the payload. Slightly more detail about the response would make it fully complete.

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 properties and schema description coverage is 100%, so there are no parameter semantics for the description to clarify. With zero parameters, the baseline is 4, and the description does not need to add parameter-level detail.

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 ('Read') and a concrete resource ('latest signed Merkle tree heads over the sealed identity and treasury logs, with the registry public key'), so the tool's function is clear. It does not explicitly contrast itself with related siblings like checkpoint_consistency or checkpoint_crank, so it misses the strongest form of sibling differentiation.

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 implies when to use the tool: whenever you need the latest signed Merkle tree heads from those logs. It also states that no authentication is needed and that the call is read-only. However, it gives no explicit guidance about when to prefer this tool over related checkpoint tools or other alternatives.

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