Create Emoji

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

Annotations already indicate it is not read-only, not idempotent, and not destructive. The description adds return info but does not discuss permissions, rate limits, or edge cases. It adds some value beyond annotations by specifying image constraints (PNG, JPG, GIF, <256KB).

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 description is concise with separate Args and Returns sections. It is front-loaded with purpose and parameter details, but the extra `roles` param adds unnecessary length.

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 creation tool with 3 parameters, the description covers purpose, parameters, and returns. However, it lacks prerequisites (e.g., 'Manage Emoji' permission), error handling info, and uniqueness constraints for emoji names. Given no output schema, it could provide more context.

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 coverage is 100%, but the description adds an optional `roles` parameter not present in the schema, causing inconsistency. It does provide additional constraints for `image_url` (file type, size) not in schema, which is helpful. Overall, it adds some value but also confusion.

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 clearly states 'Create a custom emoji in a server,' using a specific verb and resource. It distinguishes from sibling tools like `discord_add_reaction` (adds existing emoji) and `discord_delete_emoji` (deletes emoji).

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?

While no explicit alternatives are given, the purpose is clear among siblings that have different actions (add, delete, list). The description provides parameter context, but lacks explicit guidance on when to use vs. other emoji-related tools.

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