as_of

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

With no annotations, the description carries the disclosure burden and does disclose the key behavioral traits: bitemporal semantics, UTC epoch seconds for when, and optional as-recorded restriction. It does not explicitly state the return shape, nil/missing-value behavior, or that the operation is read-only, but 'query' strongly implies a non-mutating lookup.

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 dense sentence plus an illustrative quote conveys the full bitemporal model without wasted words. The key concept is front-loaded and every phrase ('CURRENT', 'UTC epoch seconds', 'as the store knew it') earns its place.

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 complex bitemporal query with no output schema and no annotations, the description supplies the core invocation semantics and even an intuitive example. It is slightly incomplete only in not describing edge cases (e.g., no value at that time, or as_recorded before when) or the exact return value structure.

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 coverage is 0%, yet the description explains all three parameters: key (the subject), when (event-time in UTC epoch seconds), and as_recorded (the record-time as the store knew it). This adds exactly the semantic meaning missing from the raw schema.

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 ('POINT-IN-TIME (bitemporal) query') and a concrete resource/result: the value current for a key at a given event-time, optionally as recorded at a later record-time. This clearly distinguishes it from retrieval siblings like recall/get_as by emphasizing bitemporal semantics.

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 a clear when-to-use framing: when you need the value current at event time 'when', or what the store believed at record time, with the user-facing quote 'What did we believe about X on date D.' It does not explicitly name alternative tools or state when not to use it, so it misses the exclusionary part of ideal guidance.

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