update_profile_image

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

With no annotations, the description fully bears the burden. It explicitly states the tool is 'DESTRUCTIVE' and that it 'immediately replaces your current profile picture.' It also documents supported formats and size limits. However, it does not mention authentication or error handling.

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 three sentences, each with high value: a clear purpose and destructiveness indicator, a specific warning, and supported file types. No fluff; front-loaded with the most critical information.

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 low complexity (one parameter, no nested objects) and the presence of an output schema, the description covers the essential behavioral aspects: purpose, destructiveness, and file constraints. It is complete for a simple mutation tool.

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 describes 'file_path' as an absolute path. The tool description adds constraints: supported formats (jpg, png, gif) and recommended max size (2MB), which are not in the schema. This adds meaningful guidance beyond the schema's generic description.

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 'Change the profile avatar image.' This is a specific verb ('Change') and resource ('profile avatar image'). It distinguishes itself from sibling tools like 'update_profile' and 'update_profile_banner' by focusing solely on the avatar.

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?

No guidance is provided on when to use this tool versus alternatives (e.g., update_profile). The description only warns about destructiveness and supported file types, leaving the agent without context for tool selection.

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