compose_screenshot

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

With no annotations, the description carries the burden of disclosing behavior. It mentions auto-uppercasing and exact store dimensions, which is helpful, but it does not disclose file writing/overwriting behavior, error conditions, or dependence on preset availability. More detail would improve transparency.

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 sentences with no fluff. It front-loads the core purpose and lists the key composing elements efficiently. Every sentence 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 10-parameter tool with a nested frame object and enums, the description provides a coherent overview of the composition process and output characteristics, while the schema details the parameters. It is complete enough for a straightforward usage scenario, though it omits some behavioral edge cases.

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 100%, so baseline is 3. The description adds semantic context by explaining that the headline is composed of verb + descriptor, auto-uppercased for the language, and that output dimensions depend on the chosen preset. This helps connect the parameters meaningfully.

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 clearly states the tool's function: 'Renders one store-ready marketing screenshot' with specific components (brand background, headline, device frame). It distinguishes from sibling tools like generate_set by emphasizing singular output ('one screenshot').

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 usage for a single screenshot but provides no explicit guidance on when to choose this tool over alternatives like generate_set. No exclusions or alternative references are given, so usage context is implied but not clearly defined.

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