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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint, and destructiveHint=false, so the safety profile is covered. The description adds genuine semantic context beyond that – it explains what the chain head represents and that it includes 'where to verify it' – though it says nothing about freshness, caching, or rate limits.

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 compact sentences, with the definition of the resource front-loaded before the usage instruction. The phrase 'with where to verify it' is slightly awkward and could be tightened, but nothing is wasted or redundant.

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?

With zero parameters and an output schema present, the description need not explain the return shape, and it correctly focuses on meaning and usage. It is essentially complete for a simple read-only getter, though a hint about when the chain head is stale or absent would add robustness.

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 takes zero parameters, so there is nothing for the description to disambiguate; per the rubric this establishes a baseline of 4. No parameter information is missing because none exists.

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 identifies a specific resource – the head of a tamper-evident verification chain – and explains its role (proving the published record was not rewritten). It is clear what the tool returns, but it never contrasts itself with siblings like live_record or trial_ledger, so an agent must infer the boundary on its own.

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?

It gives an explicit use case: 'Use it to check that a figure you read was not changed later,' which tells the agent when this tool is the right call. However, it names no alternatives and states no conditions under which this tool should be avoided in favor of a sibling.

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