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

With no annotations, the description carries the full burden of behavioral disclosure. It clearly states that the server is paid from balance, that a topup must confirm first, that insufficient balance returns a structured response with deficit and suggested amounts, that omitting account_token creates a new account whose token must be stored, and that the server is active immediately.

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 dense but front-loaded, with the core constraint stated first. Every sentence carries a distinct operational fact: topup prerequisite, insufficiency-handling flow, account-token behavior, and immediate activation. The length is justified by the payment and retry complexity.

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 9-parameter, payment-dependent tool with no output schema, the description covers the critical lifecycle: required topup, error/retry shape, account creation, and immediate activation. The main gap is that the successful return payload is not described and there is no reference to siblings like list_plans or list_locations for populating required fields, but the core flow is largely complete.

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?

The description adds real meaning for account_token — saying a missing token triggers account creation and requires storing the returned token — which goes beyond the schema's 'optional Bearer token.' However, the overall parameter coverage is only partial, and required plan and location values remain undocumented in both the schema and the description, so the gains are uneven.

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 opens with a specific verb and resource: 'Deploy a server from your USD balance.' It also distinguishes itself from siblings by declaring the BALANCE-ONLY constraint and referencing topup_create and topup_bonus, so an agent can clearly separate the creation flow from quote, server_action, or account_balance.

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 gives an explicit prerequisite: 'you must topup_create first (min $30, see topup_bonus for free credit tiers), wait for the topup to confirm, then call this.' It also defines the retry path when insufficient_balance is returned, effectively telling the agent when not to proceed and what to do instead.

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