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

With no annotations provided, the description carries the full burden. It explicitly states 'Read-only' and outlines the membership benefits, giving the agent a clear understanding of what the tool does without side effects. It could mention edge cases like invalid address handling, but the core behavior is transparent.

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 long and front-loaded with the action. The second sentence provides dense, useful context about benefits and usage, without redundant fluff. It's slightly long but each clause earns its place, so 4 is appropriate.

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 simple read-only check with one parameter, the description covers purpose, usage, and behavior. No output schema exists, so the description reasonably indicates the output involves membership status and benefits, though it doesn't specify exact return format or error handling. This is a minor gap, so 4.

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 input schema has 100% coverage for the single 'address' parameter with a clear EVM address description. The tool description adds no extra semantics beyond the schema, so the baseline of 3 applies.

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 checks whether an address holds a recognised member NFT and what benefits it gets. It uses a specific verb ('Check whether') and resource ('an address'), and the mention of membership benefits distinguishes it from routing/quoting siblings like robyn_quote and robyn_cross_chain.

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 instructs to call this before quoting a user, providing a clear context for use. It implies the tool informs accurate cost quotes and savings for non-members, but it does not explicitly name alternative tools or specify when not to use it, so it falls short of a 5.

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