render_screen

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

With no annotations, the description must carry behavior itself, and it does: it states the return value ('image path and a manifest entry'), automatic text-discipline transformations, and a latency warning ('takes a few minutes'). It does not cover persistence/cleanup details, but those are secondary for a render tool.

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 appropriately sized, front-loads the core purpose, and every sentence contributes information (inputs, consistency, automation, output, latency). It is slightly dense, but not padded.

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 tool with no output schema, the description covers the return type, runtime cost, and automatic behavior, which is the context an agent needs beyond the parameter schema. It could more explicitly address the sibling tool and clarify the product parameter, but the essential calling context is present.

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 90%, so the schema already documents most parameters; the description adds useful guidance about shared sidebars, active item, and text-discipline constraints. However, it lists optional sidebar/active as if part of the core call and omits the required 'product' parameter, and its 'dark theme' phrasing sits awkwardly with the theme enum that allows light.

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?

Starts with a specific action and resource: 'Render one UI screen mockup with the local qwen pipeline.' The 'one UI screen' scope distinguishes it from the sibling generate_product, and the rest of the description clarifies it is a single-screen rendering tool rather than a product generator.

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 implies use when you need a single UI mockup and adds practical context ('for consistency across a product', 'takes a few minutes'), but it never names the sibling generate_product or states when to use one tool instead of the other. No exclusion criteria or explicit alternatives are provided.

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