Jev prepared tool-call router

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

The description adds behavior beyond the readOnly/idempotent annotations by disclosing that the server never executes the selected call, that it returns null when no selection is confident, and that authorization and validation are trusted host responsibilities. These are operationally important traits not visible from the annotations.

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?

The description is five short sentences with the central purpose first and supporting safety/usage constraints after. Every sentence contributes a distinct fact: no generation, host responsibilities, null fallback, no execution, and the sibling alternative.

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 the core routing behavior, the description is complete and aligns with the rich candidate schema and annotations. However, it never explains the purpose of required top-level inputs such as task and observation or optional controls like review_at and auto_accept, so an agent has clear but incomplete guidance.

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 only 17%, and the prose does not compensate for the top-level parameters: task, observation, model, review_at, and auto_accept are left unexplained. The candidate-array semantics are covered, but the required task/observation fields and control parameters remain ambiguous.

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?

Description opens with a specific action 'Choose among up to 32 exact host-prepared tool calls' and explicitly excludes generating arguments or invoking a partner model. It closes by naming the sibling for generation, so the tool's identity is distinct from jev_coding_loop.

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 states the primary use case (selecting a confident, suitable, complete, low-risk prepared call) and a concrete exclusion/alternative: use jev_coding_loop when new generation may be necessary. It also tells the agent that empty/ineligible candidate lists should return locally without calling Jev, which is a clear when-not-to-invoke rule.

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