send_image

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

Annotations already indicate readOnlyHint=false (mutates). The description adds context: 'same rate limiting and dedup as send_message', 'sent as QQ-native image', and explicitly states 'Mutates the chat'. No contradictions with annotations and adds useful behavioral details.

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 five sentences without wasted words. Each sentence adds distinct value: purpose, sibling alternatives, exclusivity, behavioral note, mutation acknowledgment. Front-loaded with the core action.

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 no output schema and 4 parameters, the description covers the core functionality but omits error handling, response format, size limits, and authentication. The openWorldHint suggests unknown side effects not clarified. Adequate but not fully 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 0%, so the description must explain parameters. It clarifies that 'image' is base64-encoded and that 'target_type' defaults to group, but does not explain 'target' format, 'reply_to', or constraints like allowed image formats/sizes. Insufficient compensation for missing schema descriptions.

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 sends a base64-encoded image to a QQ group or friend. It explicitly distinguishes from siblings like send_message, send_voice, and send_file, leaving no ambiguity about what the tool does.

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 provides explicit when-to-use guidance by referencing siblings: 'For text messages use send_message. For audio use send_voice. For files use send_file. This tool only sends images.' It lacks mention of prerequisites or edge cases but is above average.

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