discord_create_emoji

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

Beyond annotations (readOnlyHint=false, idempotentHint=false, destructiveHint=false), the description discloses the permission gate, a server-wide quota tied to boost tier, the failure mode ('rejects the upload with a clear error once the cap is reached'), and accepted image forms and size limit. That is exactly the operational context annotations cannot carry.

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?

Front-loaded with the action, then constraints in roughly the order the agent will hit them (name rule, image input, permission, quota). Four sentences, no preamble, and the closing 'Returns the created emoji' is the only mild redundancy given an output schema exists.

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 mutating tool with a rich schema, output schema and annotations, the description covers permissions, quota, input formats and failure behavior, which is most of what an agent needs. The gaps are the undisclosed role_ids restriction (a real behavioral choice about who can use the emoji) and the 256 KB vs 10 MB size discrepancy that should be reconciled.

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; the description restates the name rule and the image format options but adds no new semantics. It also never mentions role_ids (scoping the emoji to roles) or reason (audit log), and its '256 KB' limit conflicts with the schema's 'max 10 MB', leaving the agent with two different size ceilings.

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?

Opens with a specific verb and resource: 'Upload a new custom emoji to the server.' The word 'new' plus the resource 'emoji' cleanly separates it from discord_edit_emoji, discord_delete_emoji and the parallel discord_create_sticker (different resource), so an agent can pick it without opening the schema.

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 gives usable preconditions ('Requires Manage Expressions', boost-tier emoji cap with a clear error) which tell the agent whether the call can succeed. It stops short of naming alternatives (e.g., discord_list_emojis to check the current count/cap, discord_edit_emoji for modifications), so routing guidance is inferred rather than explicit.

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