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

The description discloses a critical behavioral trait beyond what annotations provide (none are given): the remote server has no local storage, so the API key is returned only once. It also explains the consequence (must store securely) and the alternative auth method (Authorization: Bearer header). This is exactly the kind of behavioral context an agent needs to avoid losing credentials.

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 paragraph of 4 sentences, front-loaded with the core purpose and the most critical warning (key returned once). It is efficient and every sentence earns its place, though it could be slightly more structured with line breaks for the key-return warning. Still, it is appropriately sized and readable.

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 tool with no output schema and no annotations, the description covers all essential context: what it does, the critical one-time key return, how to use the key afterward, and when to skip it. It also names the sibling tool (whoami) for checking credentials. Nothing an agent needs to call it correctly is missing.

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 100%, so the schema already documents all 5 parameters. The description adds context for the 'nanoAddress' parameter ('the wallet this agent pays from') and clarifies the 'callbackUrl' purpose ('signed order state-change events'), but these are minor additions. Baseline 3 is appropriate since the schema does the heavy lifting.

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 tool's function: 'Creates a Nagora agent and mints its API key in one call.' It uses a specific verb ('Creates') and resource ('Nagora agent'), and explicitly distinguishes itself from the sibling tool 'whoami' by noting it should be skipped if a credential is already configured. This makes it easy for an agent to select it correctly.

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 explicit when-to-use and when-not-to-use guidance: 'Skip this tool if a credential is already configured; check with whoami.' It also explains the critical usage pattern: the key is returned once, must be stored securely, and passed as apiKey on subsequent calls or via Authorization header for long-lived setups. This is comprehensive and actionable.

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