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

The description adds meaningful behavioral context beyond the sparse annotations (readOnlyHint=false, openWorldHint=false). It discloses the return type, the user approval flow, and the need for polling asynchronously. This adequately informs the agent about the tool's operational characteristics, though it doesn't cover edge cases like duplicate registrations.

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 sentence that is front-loaded with the primary purpose and flows logically to the return value and next steps. Every clause contributes necessary information without redundancy, making it appropriately concise.

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 simple tool (no output schema, all parameters documented, no nested objects), the description fully conveys the expected flow: register, receive pairing info, user approval, then poll a sibling tool. This is complete for an agent to invoke the tool correctly.

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 has 100% coverage with clear descriptions for all three parameters (platform, description, proposed_name), including examples. The description adds no additional parameter explanation, so it meets the baseline for schema-heavy contexts without going beyond.

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 ('Register this agent with Yo'), the resource (agent with Yo), and the unauthenticated nature. It also distinguishes itself from sibling tools by describing the return value (pairing URL and code) and the follow-up step (poll check_registration), making it clear this is the initial registration step.

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 a clear usage context: use this to start registration, then poll check_registration for the API key. It explicitly mentions the alternative/sequel tool, which helps an agent decide when to use it. However, it doesn't mention when not to use it (e.g., if already registered), so it misses explicit exclusions.

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