Change chat / channel avatar

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

Annotations include openWorldHint and idempotentHint, which already indicate the tool modifies external state and is idempotent. The description adds the useful context that the photo can come from a local path or URL and implies replacement of the existing avatar. However, it does not disclose potential side effects like whether the old avatar is deleted or if specific permissions are required.

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 a single, clear sentence that is immediately understandable. It avoids unnecessary words and gets straight to the point, making it easy for an agent to parse.

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?

The tool is simple but lacks essential context. Required parameters 'peer' and 'path' are not explained, the difference from set_profile_photo is not stated, and there is no output schema or additional behavior described. An agent would struggle to know what values to pass for 'peer' and 'accountId'.

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?

With 0% schema description coverage, the description must explain parameters. It only clarifies 'path' by stating it can be a local path or URL, but leaves 'peer' and 'accountId' unexplained. 'peer' is required and critical for selecting the chat/channel, so the lack of explanation is a significant gap.

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 'Upload a new avatar photo from a local path or URL' clearly states the action (upload) and the resource (avatar photo). The title 'Change chat / channel avatar' clarifies the target, distinguishing it from user profile photo tools like set_profile_photo. However, the description alone does not explicitly mention 'chat/channel', so it relies on the title for full sibling differentiation.

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 no guidance on when to use this tool versus alternatives. It does not mention that this is for chat/channel avatars specifically, nor does it contrast with set_profile_photo or other avatar-related tools. No exclusions or prerequisites are stated.

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