build_sign_in_payload

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

The description is consistent with readOnlyHint=true and openWorldHint=false — it only assembles an encrypted payload locally rather than performing sign-in. Beyond that it adds little: no statement about side effects, determinism, or that the wallet signature must already exist before calling. With annotations carrying the safety profile, a 3 fits.

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?

Two sentences, both earning their place: the first defines the operation, the second routes the result to the consumer tool. Purpose is front-loaded with zero padding.

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?

No output schema exists, yet the description says only "Returns the payload" without characterizing the computedData object an agent must pass to managed_sign_in. For a 6-parameter builder feeding a downstream call, that return-value gap and the missing provenance of nonce/signature leave it only minimally sufficient.

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 100%, so all six parameters (five required) are documented in the schema itself. The description's phrase "from raw credentials" only gestures at the input set and adds no format or dependency detail beyond what the schema provides — baseline 3.

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?

States a specific verb and artifact: "Build the encrypted sign-in computedData payload from raw credentials." The second sentence disambiguates it from its close sibling managed_sign_in by positioning this tool as the payload producer, not the sign-in executor.

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?

"Returns the payload to use with managed_sign_in" gives clear flow guidance — build first, then submit with managed_sign_in. It stops short of naming where nonce/signature/sessionKey come from (e.g. generate_session_keypair) or when an alternative auth path (auth_login, oauth_login) applies, so no explicit exclusions.

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