update_profile_picture

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

With no annotations, the description carries full burden for behavioral disclosure. It states the tool performs an update (implying mutation) but does not elaborate on permissions required, side effects (e.g., overwriting previous picture), or constraints on the input format beyond what the schema already provides. The description adds minimal behavioral context beyond the schema.

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, concise sentence with no unnecessary words. It front-loads the action and resource efficiently, making it easy for an agent to parse quickly.

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 simple tool with two parameters and no output schema, the description is adequate but incomplete. It does not mention that the instance must exist, any validation of the picture input, or what happens on success/failure. Given the context of siblings (e.g., remove_profile_picture), more context would help.

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 100% (both parameters have descriptions). The description adds no additional meaning beyond the schema, as it merely restates the allowed formats ('URL or base64') already present in the schema. Baseline score of 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 clearly states the action ('Update') and the resource ('profile picture of the instance'), and specifies the allowed formats ('URL or base64'). It effectively distinguishes this tool from siblings like 'remove_profile_picture' and 'fetch_profile_picture_url' by indicating modification rather than removal or retrieval.

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 vs. alternatives such as 'remove_profile_picture' or 'fetch_profile_picture_url'. The description lacks any context about prerequisites, preferred scenarios, or exclusion criteria.

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