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

With no annotations, the description discloses the core effect (extends TTL, max lifetime) and the payment requirement. It does not mention side effects, errors, or edge cases (e.g., id not found), but the primary behavior is transparent. Given the lack of annotations, it carries the full burden and could be more detailed.

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, focused sentence. It packs the essential action, constraint, and requirement without any fluff or redundancy. Information is front-loaded, making it easy to parse.

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 the purpose, effect, and requirement, which is sufficient for a simple one-parameter mutation. However, it omits explanation of the 'id' parameter and does not mention any output or return value. Since the schema provides no additional detail, this leaves some ambiguity for the agent.

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 only parameter 'id' has no schema description, and the tool description does not clarify what it refers to (though it implies a memory identifier). Without explicit context, an agent might not know exactly what id to supply, making this a notable gap.

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 a specific verb ('extends') and resource ('memory's TTL'), with concrete details (by 30 days, max 365 days from creation). It distinguishes this from siblings like read_memory or store_persistent_memory by focusing on the TTL extension action.

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?

It implicitly defines when to use the tool (when extending a memory's TTL) and mentions a requirement (x402 payment). It does not explicitly contrast with alternatives, but the operation is distinct enough that the context is clear.

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