Get an API key — no account, one call

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

Annotations are minimal (only openWorldHint: false), so the description carries most of the behavioral burden. It discloses that the key is shown only once, a critical warning, and clarifies that the tool is a mutation (creates a workspace) without needing destructive flags. It also notes the keyless prerequisite. While it doesn't mention idempotency or rate limits, the one-time key display is a significant behavioral disclosure that goes beyond the annotation.

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 two sentences, front-loaded with the core action and the crucial one-time key warning, followed by the key storage instructions. Every clause earns its place, and the tone is direct. No fluff or redundant information.

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 two optional parameters, no output schema, and minimal annotations, the description is nearly complete. It explains the output (API key), the prerequisite (keyless connection), and the follow-up (store and reconnect). Minor gaps like what happens on repeated calls or rate limits are not addressed, but they are non-critical for a signup tool. The description is sufficient for an agent to use it correctly in most scenarios.

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 coverage is 100%, with both 'ref' and 'name' already described in the input schema. The description adds minimal extra semantics, merely confirming that the workspace name is tied to the 'name' parameter. Since the schema already covers the parameters, the description doesn't need to compensate, but it also doesn't enrich them further. Baseline 3 is appropriate.

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 creates a workspace and returns an API key, distinguishing it from all sibling tools by noting that 'every other tool needs the key.' This makes it obvious that signup is the bootstrap step for keyless connections. The verb 'creates' and resource 'workspace' are specific, and the one-time key display warning is prominent.

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 states the tool works on a keyless connection and that all other tools require the key, establishing a clear precondition and when-to-use. It also gives concrete instructions on where to store the key (plugin setting, header, or environment variable) and to reconnect afterward, leaving no ambiguity about the follow-up action.

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