set_image_source

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

With no annotations, the description carries full responsibility for behavioral disclosure. It states the mutation effect ('rewrite its sourceFile'), accepted input forms, and a preservation detail ('Preserves the visual's current scaling'). This is more transparent than typical mutation tools, though it does not mention permissions or reversibility.

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?

Two sentences, front-loaded with the core purpose, followed by key source-type and scaling details. Every clause earns its place, with no repetition of schema content.

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 no output schema and no annotations, the description covers the essential context: existing visual, source format, and scaling preservation. It lacks explicit prerequisites (e.g., active report session) or return/error behavior, but for a simple update operation it is reasonably complete.

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 75% with descriptions for page, visual, and imageUrlOrPath. The description adds marginal detail like '(embedded)' for imageUrlOrPath and 'sourceFile' terminology, but does not explain reportSessionId. The schema already handles most parameter meaning, so baseline 3 is appropriate.

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 uses a specific verb and resource: 'Re-source an EXISTING image visual: rewrite its sourceFile to a new image.' It clearly distinguishes from the sibling tool add_image by noting 'add_image only creates new ones.' This makes the tool's purpose unambiguous and differentiates it from related tools.

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 explicitly frames when to use this tool versus add_image: 'add_image only creates new ones,' implying set_image_source is for existing visuals. It also gives concrete guidance on accepted URL/file types ('local file (embedded) or an http(s)/data URL'), which helps the agent decide if this tool fits the input.

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