create_placeholder

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

With no annotations provided, the description carries full burden for behavioral disclosure. It only states the tool generates a low-quality image placeholder; it does not describe output format implications, side effects (e.g., creating files), internal processing, or prerequisites. This is insufficient for a tool with 7 parameters and no annotation safety hints.

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 a single, compact sentence that is front-loaded with the action and outcome. There is no fluff or redundant information; every word 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?

The tool has 7 parameters, no annotations, and no output schema, so a one-line description is somewhat minimal. However, the rich schema covers parameters, and the core behavior is simple enough that it is adequately described for basic use. The missing aspects are more about behavioral transparency (output details) and usage alternatives, which are scored separately.

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%, so all parameters are already documented in the schema. The description adds no extra context about parameters, but per the rubric, baseline is 3 when coverage is high. The description does not compensate further, but it doesn't need to.

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 action ('Generate') and specific resource ('low-quality image placeholder'), with an explicit purpose ('for lazy loading'). This distinguishes it from siblings like optimize_image, which focuses on optimization rather than placeholder generation.

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 phrase 'for lazy loading' implies a use case, but the description does not explicitly contrast with alternative tools (e.g., optimize_image) or state when not to use this tool. The guidance is implied rather than explicit, missing exclusions or alternative recommendations.

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