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

With no annotations available, the description carries the full burden for behavioral disclosure, but it only hints at a precondition (payment) and workflow step. It does not explain side effects, error behavior, or whether the key is returned directly, leaving an agent to guess about failure modes.

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, front-loaded sentence with no filler. Every word contributes to the core purpose and the parameter's role.

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 one-parameter tool with no output schema or annotations, this description is adequate but has gaps: it does not specify what happens if the order has not been paid, whether the key is returned directly, or any authentication requirements. An agent may still be unsure how to handle errors.

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 explains that 'order_id' is the identifier used to collect the key, adding meaning beyond the bare schema property name. However, with 0% schema description coverage, more could be said about expected format or relationship to the invoice.

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 identifies a specific verb ('collect') and resource ('API key') with a required parameter ('order_id'), making the tool's purpose understandable. It does not explicitly differentiate from sibling tools, but the object and parameter are specific enough to be distinct.

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 context by stating 'After paying the invoice', which tells the agent when this tool is appropriate. It does not mention exclusions or alternatives, but the conditional preposition is reasonable guidance for a simple retrieval tool.

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