Change a Discord member's nickname in a server; pass an empty string to reset it to their original username.
Change a member nickname in the server (empty string resets to original username)
| Name | Required | Description | Default |
|---|---|---|---|
| reason | No | Audit log reason | |
| userId | Yes | Member User ID | |
| guildId | No | Discord server ID (defaults to DISCORD_GUILD_ID) | |
| nickname | No | New nickname (leave empty or null to reset) |
Changes observed during successful MCP inspections.
v1.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden. It does disclose the useful reset semantic (empty string restores the original username), but it omits permission requirements, whether the bot can rename members other than itself, rate limits, and reversibility of the change.
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?
A single sentence that front-loads the core action and parenthetically states the important edge case. Nothing is wasted.
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 mutation tool with no annotations and no output schema, the description covers the key edge case but leaves behavioral gaps (permissions, error conditions, audit-log implications of the reason param) that an agent would want before calling it.
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 four parameters are already documented in the schema. The description's only additive point is the reset behavior, which the schema's nickname description also covers, so it does not add meaning beyond the schema. Baseline 3 applies.
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 gives a specific verb+resource ("Change a member nickname") scoped to the server, which is unambiguous. It does not distinguish itself from any sibling, though no sibling directly competes for nickname modification, so this is a minor omission.
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 states the reset edge case but gives no guidance on when to use this tool versus alternatives or any preconditions. There is no explicit when-to-use or when-not-to-use context.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.