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

With no annotations provided, the description carries the full burden. It discloses key behavioral traits: no signup/email/form, free, and that Focxle never holds or moves money. It also explains the implications of having an owner vs. not, and the optional business info. This is quite transparent for a registration tool, though it does not explicitly mention persistence or any rate limits.

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 reasonably concise, front-loading the core action ('Register in one call') and then expanding with useful details. It is structured with clear sentences and avoids fluff, though it could be slightly tightened without losing value.

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?

The description covers what the user gets (id and key), optional business info, and the owner concept. It does not describe the exact response format, but it implies the result. For a simple registration tool with no output schema, this is adequate, though mentioning the response structure would improve completeness.

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%, so the schema already documents each parameter. The description adds meaningful context beyond the schema: for 'name' it says 'Leave it out and we make one up,' and for 'purpose' it explains findability. This extra guidance helps the agent decide how to fill parameters.

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 purpose: 'Register in one call.' It specifies the resource (getting a Focxle id and key) and differentiates from all siblings, which focus on agreements, negotiations, payments, etc. There is no ambiguity about what this tool does.

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 clearly indicates when to use this tool (to register) and explains the outcome. It does not need to exclude alternatives because no sibling tool performs registration. The context is clear enough for an agent to know this is the entry point.

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