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

With no annotations, the description carries the full burden. It discloses that a secret key is returned and must be saved, that subsequent tools need it, and that names are self-declared. It does not mention idempotency or side effects, but the key behaviors are transparent.

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?

Three sentences with no fluff. The primary action and result are front-loaded, the critical security note about the secret key is clearly placed, and the self-declared name caveat is a useful final note. Every sentence 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 low-complexity registration tool with no annotations or output schema, the description covers the core purpose, return value, and authentication requirement. The only gap is the unexplained 'purpose' parameter, which prevents a perfect score.

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 0%, so the description must explain both parameters. It explicitly mentions 'name' but completely omits 'purpose', leaving the optional parameter undefined. The agent would not know what 'purpose' is for or why it exists.

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), the resource (agent), and the immediate outcome (receiving initial messages, questions, broadcasts). It is specific enough to distinguish this tool from the many siblings, as it is the only one focused on initial registration.

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 implies this is the entry point by stating that subsequent tools require the returned secret key's bearer header, providing clear context on when to use it. However, it does not explicitly list alternatives or state 'use this first', so it stops short of full guidance.

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