add_numbered_callout

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It reveals the auto-increment feature, which is useful, but it omits other important behaviors: it does not state that the tool mutates the image, whether changes are persistent or undoable, or what the output schema contains. The description is too sparse to give an agent confidence about side effects.

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 concise at two sentences and front-loads the primary purpose. It avoids redundancy with the schema and wastes no words. The auto-increment note is a useful addition that earns its place. Minor deduction for not being structured with clear separation, but overall it is efficient.

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?

Given the tool has 7 parameters and an output schema, the description is too brief to be contextually complete. It does not mention coordinate system, prerequisites (e.g., image must be loaded), the relationship to reset_callout_counter, or any details about the output. An agent lacks key information to correctly invoke the tool in a workflow.

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 input schema provides 100% coverage with descriptions for all 7 parameters. The description adds no new parameter-specific meaning beyond what the schema already states (e.g., the 'number' parameter's auto-increment behavior is already in the schema). Since coverage is high, the baseline of 3 applies, and the description does not elevate it.

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 action ('Add a numbered callout') and the resource (image). It also notes the auto-increment behavior, which differentiates it from other annotation tools like add_text or add_circle. However, it doesn't explicitly distinguish it from siblings like add_text with a number, but the term 'callout' implies a circled number, so it's mostly clear.

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 gives no explicit guidance on when to use this tool versus alternatives. It implies usage for sequential callouts via auto-increment, but does not mention when not to use it, nor does it reference the related sibling tool reset_callout_counter, which directly affects the auto-increment behavior. An agent is left to infer the appropriate context.

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