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

Annotations only declare readOnlyHint=true, and the description adds genuinely useful context: it documents the required Proof account and the exact auth flow plus the explicit exclusion of start_login. It does not disclose failure behavior when unauthenticated, but the auth requirement is a real addition beyond annotations.

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 clearly separated blocks – purpose and access – with the primary function front-loaded. Efficient, though the all-caps 'ACCESS' header is slightly heavy for the amount of content.

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?

Complete for a zero-param read tool: it states what is returned, that it is read-only, and the auth precondition that would otherwise cause silent failures. Without an output schema it could be more explicit about the response shape, but the field list covers the essentials.

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?

Zero parameters, so baseline is 4. The description adds value by naming the returned fields a caller can expect, which compensates for the absent output schema, though with no params there is nothing more to specify.

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 (get) and resource (current user's primary profile) and enumerates the returned fields (details, theme, custom links, public proof display settings). Siblings get_profile and get_current_user exist, and the phrase 'current user's primary profile' distinguishes this from retrieving an arbitrary profile by ID.

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?

Provides explicit conditional guidance for the authentication prerequisite ('Authenticate this client, then call this tool again') and explicitly rules out start_login as the path to this tool. It does not contrast against get_profile / get_current_user, but the when-to-use context is clear.

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