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

Annotations already carry readOnly, idempotent, closed-world, and non-destructive hints, so the safety profile is covered. The description adds the hashing algorithm (SHA-256) and the content-addressed property, which explains why identical content yields identical IDs, but it omits what happens when both inputs are empty (required set is empty) and what the return value looks like.

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?

A single front-loaded sentence that identifies the tool, its mechanism, and its domain with no filler or redundancy.

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 simple deterministic ID tool with rich annotations and full schema coverage this is close to sufficient, but with no output schema the description should say the result is a hex digest string, and it should clarify behavior when neither optional input is supplied.

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% and both parameters are documented with encoding and preference guidance, so baseline 3 applies. The description itself adds no parameter-level meaning beyond naming SHA-256 as the hashing scheme.

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 the resource (FactLot document ID), the derivation method (content-addressed, SHA-256), and the input domain (lease, amendment, estoppel), which separates it from sibling identifiers like id_entity, id_parcel, and id_space. It never states the operative verb explicitly ('compute'/'derive'), leaving the action implied rather than declared.

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?

Listing document types (lease, amendment, estoppel) hints at the domain but gives no when-to-use rule and no comparison against alternatives; nothing tells the agent why it would pick this over id_parse or id_entity. It also offers no guidance on the text-vs-bytes choice beyond what the schema already says.

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