add_text

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It only says 'add text annotation to the image,' revealing nothing about how the annotation is applied (e.g., overlay coordinates, persistence, impact on the image) or anything about the operation's side effects. This is insufficient for a tool with zero annotation coverage.

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, concise sentence with no wasted words. It front-loads the core action. However, it is perhaps overly terse—while concise, it omits context that could be included without becoming bloated. Still, it is clearly structured and readable.

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?

With 7 parameters and an output schema, the description is not complete for an agent to make a confident choice. It gives zero context on coordinate systems, how it relates to image state, or how it differs from other annotation tools. Since output schema exists, return values are covered, but the operational context is missing.

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?

The schema documents all parameters with descriptions, so schema coverage is 100%. The description itself adds no additional parameter meaning beyond what the schema provides, which meets the baseline for high coverage. A 3 is appropriate since the description doesn't hint at coordinate semantics, font sizes, or color usage beyond the schema.

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 a specific action (add text annotation) on a resource (image). However, it does not differentiate from many similar sibling tools like add_box, add_circle, or add_highlight; an agent would still need to infer which tool is for text annotation versus other annotation types.

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?

There is no guidance on when to choose this tool over alternatives. The description does not mention that it is for text-only annotations, nor does it reference the many sibling annotation tools such as precise_annotate, annotate, or add_numbered_callout. An agent receives no context about selection criteria.

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