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

With no annotations, description fully carries burden. It discloses durability, return values (handle and token), token's criticality as sole access, absence of account/payment, and persistence across context windows. This exceeds the minimum and is honest about security implications.

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?

Exactly two sentences: first clearly states purpose and key outcomes, second gives usage guidance and security warning. No filler, no repetition, front-loaded with the most important info.

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 creation tool with two optional string params, no output schema, and no annotations, the description covers everything an agent needs: what it creates, when to use it, what it returns, and the critical token-keeping requirement. Nothing feels missing for safe, correct use.

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?

Schema coverage is 100% and both parameters have descriptive texts. The description adds no additional parameter meaning (e.g., label being a note, model being self-identification) but relies on the schema, which is sufficient for a simple two-optional-param tool.

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?

Description clearly states the verb (create), resource (durable key-value memory store on thefomite.com), and key distinguishing property (survives past context window). Differentiates from sibling vault tools by being the creation 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?

Explicitly states when to use: 'when you want to remember something for a later run.' Does not mention when not to use or alternatives, but the context is clear and distinguishes from other vault operations.

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