state_digest

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

With no annotations, the description carries full behavioral disclosure burden. It does so admirably, stating determinism, order-independence, scope (covers recallable state), and the precise meaning of a changed digest. This tells an agent what kind of state mutation signals to infer without claiming any 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, each earning its place: the first defines what the tool computes, the second gives the canonical usage pattern, and the third situates it among siblings. The most essential facts are 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?

For a zero-parameter tool with an output schema present, the description is complete. It covers what the tool does, how to use it, what a changed result means, and how it relates to nearby heavier tools. Nothing needed for correct invocation is missing.

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 and the input schema is empty, so the schema already covers everything. The description adds value by confirming the operation is a stateless fingerprint computation on the current store state, aligning with the 0-parameter baseline.

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 names a specific operation: compute a deterministic SHA-256 fingerprint of the current store state. It clarifies key characteristics (order-independent, covers what recall can serve) and distinguishes itself as the lightweight sibling of witness()/anchor(), so an agent can separate it from nearby tools without opening schemas.

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 gives a clear workflow: pin the digest, do work, compare later, with a changed digest meaning a write/supersession/revert/erasure occurred. It positions the tool as the lightweight alternative to witness()/anchor(), implying when to prefer it, though it stops short of explicit when-not-to-use conditions.

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