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

The annotations declare readOnlyHint=true, but the description advertises 'save' and 'delete' operations, which are writes and destructive deletes respectively. This is a direct contradiction of the structured safety profile. The genuinely useful added context (2,000 keys/wallet, 16,000 chars/value, $0.003 USDC per x402 call, EVM wallet payment) cannot offset a misleading read-only signal.

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?

Three tight sentences, front-loaded with the purpose, then operational limits, then the payment requirement. Almost no waste, though the payment details are split across two sentences that could be one and the action list partly duplicates the schema.

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 5-parameter multi-action CRUD tool with no output schema and contradictory annotations, the description covers limits, cost, privacy, and persistence but says nothing about per-action behavior (what get returns, whether delete is reversible, error/not-found behavior). It is adequate but leaves real gaps.

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 description coverage is only 40% — key, limit, and value carry no schema descriptions, and the description never explains what they mean or their formats/units. The description's verb list merely restates the action enum already documented in the schema. With low coverage and no compensating detail, it falls short of the baseline.

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?

Names the resource (agent memory notes) and the five concrete verbs (save, get, search, list, delete) plus the defining trait of cross-session persistence and wallet-scoped privacy. An agent knows exactly what this tool does. It does not, however, differentiate itself from nearby siblings such as storage, kb, or context, which also hold data.

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?

Usage is implied rather than stated: 'notes that persist between sessions' tells the agent this is for durable agent state, and the payment line implies it is a paid call. There is no explicit when-to-use/when-not guidance and no mention of the alternative stores among the siblings, so the agent must infer selection.

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