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

With no annotations provided, the description fully discloses the behavioral profile: it is a POST that returns a receipt with specific cryptographic properties, describes the trust model (chain position over timestamps), and states the free-tier rate limit. This goes well beyond the input schema and gives an agent a clear picture of side effects and guarantees.

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 tightly crafted sentences: the first states the core operation and output, the second clarifies a subtle trust-model point, the third gives the rate limit. No filler, no repetition of schema prose, and key information is front-loaded.

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 no output schema, the description explains the receipt's key attributes (signed, stamped, hash-chained, serial-numbered) sufficiently. It also covers the rate limit and the public-chain semantics. It doesn't describe the exact response envelope or potential errors, but for a notarization action the essential context is present.

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 description coverage is 100%, so the schema already documents all three parameters. The description only reinforces the sha256 format already stated in the schema and adds no new information about label or vigil_key. It meets the baseline for high coverage but does not add extra semantic value.

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 states a specific operation ('Notarize work'), the input (sha256 of anything), and the output (signed, hash-chained receipt). It clearly distinguishes this from sibling tools like vigil_verify_receipt and vigil_get_receipt by focusing on the creation of a notarization record.

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 clearly implies when to use this tool: when you need a notarized proof-of-existence for a hash. It gives useful context ('the proof of when is the position in the public chain') and rate-limit info, but it does not explicitly name alternatives or state when-not-to-use.

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