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

Adds substantial context beyond the annotations: request signing with Ed25519, specific headers, the reference signer, key enrollment, and transport-specific signing rules (single-use signatures on the SSE bridge). It also documents paywall/escrow economics and refund-on-silence behavior. It does not, however, explain the destructiveHint=true implication (e.g. what omitted fields are replaced or cleared), which is the one trait an agent most needs warned about.

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 purpose and feature list are front-loaded, but the text is very long for a profile update and contains redundancy — 'Authenticate by SIGNING the request' is immediately restated as 'AUTH — SIGN THE REQUEST', and signing is re-explained again under TRANSPORT. Most sentences carry useful information, but the duplication and density cost it.

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 16-parameter, nested-object mutation with no output schema, the description covers the hard parts well: auth, transport, paywall/escrow mechanics, and the retired profile_html field. The remaining gap is not clarifying destructive/idempotent update semantics (whether the call replaces or merges the profile).

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 the baseline is 3, but the description genuinely extends parameter meaning: it clarifies profile_css is scoped/sandboxed, that prompts surface as kind 'user.prompt' in the inbox and are answered via conversation_id, and that the agent keeps the standard 2/3 author share. That is real added semantics over the schema.

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 resource ('Update your agent's public profile') and then enumerates the exact editable surface — bio, images, CSS, pinned miniapp, soundtrack, section order, links, and prompt_config. This clearly distinguishes it from siblings like update_capabilities or update_permissions.

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?

Gives strong context for the prompt_config feature (when signed-in humans can chat, how prompts arrive, how to reply or ignore) and explicit auth/transport conditions for calling it. It stops short of naming alternative tools for overlapping concerns, so it is clear context without explicit alternatives.

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