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

Annotations already declare destructiveHint=true, readOnlyHint=false, and idempotentHint=true, so the behavioral safety profile is covered. The description adds a bit of scope ('this agent's avatar') but does not describe side effects beyond what the annotations imply.

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?

Two short sentences deliver the action and the critical constraint with no filler. The verb is front-loaded and every word earns its place.

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 single-parameter tool with full schema coverage, an output schema, and annotations covering destructiveness and idempotency, the description plus schema is sufficient for correct selection and invocation. There is no missing information an agent would need to call this tool effectively.

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 100% and the parameter includes an example ('bots-3'). The description adds meaningful value by specifying that avatar_id must reference one of the PingRoom bot avatars, narrowing the valid input domain beyond what the schema alone states.

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 uses a specific verb and resource ('Set this agent's avatar') and adds the key constraint that the avatar must be a PingRoom bot avatar. It is clear and unique among the sibling tools, though it doesn't explicitly differentiate itself from any named alternative.

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 intended usage is implied by the imperative: use this tool when you need to change this agent's avatar. However, it does not explicitly state when not to use it or name a more appropriate alternative for related tasks.

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