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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint=false, covering the safety profile. The description adds valuable behavioral context beyond those annotations by specifying the exact payload returned (email, verified status, avatar hash, etc.) and the scope restriction to the current user only.

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 well-structured sentences with no fluff: the first establishes purpose and return fields, the second adds a scope limitation. The most important information is front-loaded, and every sentence earns its place.

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 parameterless, read-only tool with no output schema, the description is complete: it states what resource is accessed, lists every meaningful return field, defines the auth context ('authorized user'), and clarifies the negative scope. Nothing an agent needs to invoke it correctly is missing.

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 tool has zero parameters and the schema description coverage is 100%, so the baseline of 4 applies. The description appropriately does not attempt to document parameters and instead focuses on return values and scope, which is appropriate for a parameterless tool.

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 uses a specific verb ('Get') and resource ('authorized Discord user's own identity') and explicitly enumerates the return fields: user id, username, global display name, legacy discriminator, email, verified status, locale, and avatar hash. It explicitly excludes other users or message content, clearly differentiating it from siblings like get_guild_member.

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?

The description clearly defines when to use the tool: when an agent needs the connected account's own identity. It also provides an explicit when-not via the statement 'This is the user's own profile only — not other users or message content,' which routes away from sibling tools that fetch other users or content.

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