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

With no annotations, the description carries the behavioral burden: it explains that the tool rewrites a prompt, returns the improved prompt and parts, and provides clarifying questions and model recommendations. The phrase 'use this before answering' communicates that this is an intermediate compilation step; no side effects or risks are materially unaddressed.

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 two focused sentences with the core purpose front-loaded. Every sentence contributes actionable information: what it does, what it returns, and when to invoke it.

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?

Coverage is complete for a low-risk rewriting tool: input is fully schema-described, return content is listed, and trigger conditions are stated. It stops short of fully disambiguating build_prompt and improve_followup, but the overall definition is sufficient without an output schema.

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%: both prompt and target are already described accurately in the input schema. The tool description adds RTCF and output context but no new parameter-level semantics, so the baseline of 3 applies.

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 verb and resource: it rewrites a rough prompt into a sharper ready-to-use prompt structured as Role, Task, Context, Format. It also lists the returned components, which adds precision and clearly distinguishes it in intent from build_prompt, though it does not name or differentiate intruments directly.

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 gives explicit when-to-use triggers: 'when the user's request is vague, or when the user asks to improve a prompt.' It does not provide when-not-to-use guidance or direct the agent to build_prompt/improve_followup, but the stated conditions are clear enough for normal selection.

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