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 explicitly states 'No arguments, nothing changes,' indicating a read-only, side-effect-free operation. It does not detail error handling or authentication requirements, which are minor omissions for a simple status check, but the core behavioral trait (no mutation) is clearly communicated.

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, tightly packed with all essential information. It is front-loaded with the primary action and output, then adds the use case and side-effect note. Every sentence earns its place with no redundancy or fluff.

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 input parameters and no output schema, the description fully covers what an agent needs: the return format (JSON with product, tier, reason, checkout URL), the trigger condition, and the lack of side effects. Nothing essential 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?

The tool has zero parameters, and the description confirms 'No arguments.' Per the scoring rules, 0 parameters earns a baseline of 4. The description adds no parameter-specific meaning because none exist, and it correctly reiterates the absence of arguments, aligning with the empty schema.

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 states a specific verb and resource: 'Report this endpoint's licence state for your token as JSON'. It explicitly enumerates the returned fields (product, tier, reason, checkout URL), making the tool's purpose unambiguous. It also distinguishes itself from sibling tools like license_activate by focusing on status reporting rather than activation.

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 a clear trigger for use: 'Call it to explain a free-tier refusal.' This tells the agent when to invoke this tool. It does not explicitly discuss alternatives or exclusions, but the purpose is distinct enough from siblings that the guidance is adequate; it could be improved by noting it is the only read-only license info tool, though that is implied.

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