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

Annotations provide little behavioral info (all false), so the description carries the burden. It discloses important constraints like rate limits and the free reclaim exception, which are critical for the agent to understand side effects. However, it does not mention error behavior or permissions.

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 extremely concise with two sentences that front-load the main action. Every sentence adds essential information with no redundancy or filler.

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 tool's simplicity (one parameter, basic operation) and existence of an output schema, the description covers purpose and key constraints. It lacks details on return values or error conditions, but those are partially addressed by the output schema and annotations.

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 schema covers 100% of the parameter 'handle' with a clear description. The tool description adds no additional semantic detail about the parameter beyond the schema, so it meets the baseline of 3.

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 'Rename your already-claimed handle,' providing a specific verb and resource. It distinguishes itself from sibling tools like 'claim_handle' by focusing on renaming an existing handle, not claiming a new one.

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 explicitly mentions rename limits (1 per 90 days + 3 per year) and the special case of free self-reclaim within the 90-day reservation window. While it doesn't explicitly state when not to use or name alternatives, these details guide appropriate usage.

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