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

Beyond annotations (readOnlyHint=true, destructiveHint=false), the description discloses the non-network, local-only behavior and that each call yields a fresh CSPRNG token — consistent with idempotentHint=false. It adds security-handling guidance (sensitive capability, never a private key). The description enriches the annotation profile without contradicting it.

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 dense sentences, each earning its place: generation spec, no-network guarantee, then storage and downstream use. The only waste is mild redundancy between 'Local-only' and 'Makes NO network call'. The primary purpose is front-loaded.

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?

With no output schema, the description carries the full burden of explaining the return value — it specifies entropy, length, and URL-safety — and the downstream consumption chain (session create/read/observe/refresh). For a 0-param, 0-output-schema tool, everything an agent needs to call it and handle its result is present.

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 is empty (0 properties, additionalProperties false), so schema coverage is trivially 100% and the baseline is 4. The description adds value by characterizing the tool's only output surface — token entropy, length, and character set — which is as much semantic meaning as a zero-parameter generator can convey.

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 opens with a specific verb+resource ('generate one caller-owned high-entropy session capability token') and pins down concrete constraints (>=256-bit CSPRNG, url-safe, 43-128 chars, local-only). This cleanly separates it from siblings like assetfare_v2_session_create (which consumes the token) and assetfare_v2_capabilities (capability management).

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 gives explicit workflow guidance: the generated token must be passed into assetfare_v2_session_create and every session read/observe/refresh operation, and stored as a SENSITIVE capability (never a private key). It stops short of naming a when-not-to-use alternative, but the storage and downstream-passing instructions make the invocation context clear.

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