send_image

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

With no annotations provided, the description carries full burden. It mentions 'monitored group or whitelisted friend' hinting at permission/access constraints, but doesn't disclose critical behavioral traits like authentication needs, rate limits, error conditions, or what 'send' entails (e.g., immediate delivery, async). For a mutation tool with zero annotation coverage, this is insufficient.

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 well-structured with a purpose statement followed by parameter explanations. Every sentence adds value, though the parameter section could be slightly more concise (e.g., combining target_type details). It's appropriately sized and front-loaded.

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?

For a 4-parameter mutation tool with no annotations and no output schema, the description covers purpose and parameters adequately but lacks behavioral context (e.g., permissions, errors, response format). It's minimally viable but has clear gaps given the complexity.

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 0%, so the description must compensate. It provides clear semantics for all 4 parameters: target (Group ID or friend QQ ID), image (Base64-encoded without prefix), target_type (group/private with default), and reply_to (optional message ID). This adds substantial value beyond the bare schema, though it doesn't explain format details like QQ ID structure.

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 ('Send an image') and target ('to a monitored group or whitelisted friend'), distinguishing it from sibling tools like 'send_message' which presumably sends text. However, it doesn't explicitly differentiate from potential image-related siblings (none exist in the list), so it's not a perfect 5.

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 mentions 'monitored group or whitelisted friend' which implies some access restrictions, but provides no explicit guidance on when to use this vs. alternatives like 'send_message' or prerequisites. It lacks clear when/when-not instructions or named alternatives.

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