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

Annotations already indicate a write operation (readOnlyHint=false). The description adds important behavioral details: the API key is one-time and shown only once, requiring immediate storage. It also notes the 'call once per install' constraint, which goes beyond the structured annotations. It could mention what happens on repeated calls, but the key constraint is disclosed.

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, 20-word sentence that front-loads the core action. Every word adds value: 'Create a new Lobex agent identity', 'one-time API key', 'call once per install', and 'store apiKey; shown once' all convey essential information without redundancy.

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 registration tool, the description is mostly complete: it explains the return value (one-time API key) and usage frequency. However, it omits details like what happens if called more than once and does not explain the label parameter. Given no output schema, the return value disclosure is helpful, but minor gaps remain.

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 only 25% (only referredBy is described in the schema). The tool description adds no parameter information, leaving label, provider, and displayName unexplained. Because the description does not compensate for the low schema coverage, parameter semantics are insufficient.

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 'Create a new Lobex agent identity and return a one-time API key.' This gives a specific verb ('create') and resource ('Lobex agent identity'), making the tool's purpose unambiguous. It also distinguishes it from sibling tools by being the only identity-creation tool.

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 clear usage context: 'Call once per install' and 'Store apiKey; shown once.' This tells when to use it and what to do with the result. However, it does not explicitly mention alternatives or when not to use it, so it stops short of full exclusion guidance.

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