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

With no annotations, the description carries the full burden. It does disclose two important behaviors: submissions are pending rather than verified Bitcoin confirmations, and no key is required. It doesn't state whether the operation is read-only, whether it has side effects, or what happens on failure. That's useful but incomplete; the pending-status caveat is valuable and prevents an agent from over-trusting results.

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 short sentences deliver the resource, the pending-status caveat, and the auth requirement. No filler or repetition. The first sentence is a noun fragment rather than a clear verb clause, losing some efficiency but not much.

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 tool with no output schema, the description should say what a call returns or does. It strongly implies that the return is the set of public timestamp submissions, but it never explicitly states the operation or output shape. The caveats are helpful, but the lack of an explicit verb leaves the tool's behavior under-specified, though the low complexity mitigates the risk.

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 is a bare object, so there are no parameter semantics to document. The description doesn't attempt to invent parameters. Its 'No key required' line is auth context, not parameter info. This meets the baseline for zero-parameter tools.

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 the resource ('public timestamp submissions to OpenTimestamps calendars') and a key attribute ('pending, not an independently verified Bitcoin confirmation'), but never states the action (e.g., list, fetch, monitor). Without a verb, the tool's operation is inferred from the plural name and zero-parameter schema rather than explicitly described. It also doesn't distinguish itself from `vigil_anchor` or `vigil_notarize` beyond the 'public' and 'no key' qualifiers.

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 provides an implied use case: public, keyless access to pending timestamp submissions. The 'No key required' line is a relevant access condition. However, there are no explicit when-to-use vs when-not-to-use instructions, no mention of alternatives such as `vigil_anchor`, and no guidance on whether this replaces or supplements other vigil tools.

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