app_emojis_create

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

Annotations already signal this is a write operation (readOnlyHint=false, destructiveHint=false), so the bar for extra behavioral context is lower. The description adds meaningful details: the 2,000-emoji quota, optional application_id behavior, upload format/size limits, recommended dimensions, and a return shape. These go beyond the annotation set without contradicting it.

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 well-structured with Markdown headers and bullets, front-loads the purpose, and keeps every section informative. The quota, constraints, example, and return format each serve a distinct purpose with no redundancy or filler.

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 create tool with three parameters, two required, the description covers all necessary context: scope, alternatives, constraints, optional parameter semantics, and return values. The presence of an output schema means return details need not be exhaustive, but the description still includes a concise return shape.

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 schema already provides 100% parameter description coverage, giving a baseline of 3. The description adds value by explaining the behavior of application_id ('omit to register it on the authenticated bot application'), stating that application_id is optional for the current bot, and giving a concrete example payload.

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 opens with a specific verb and resource: 'Upload a new application-scoped custom emoji.' It clearly distinguishes this tool from the sibling emojis_create by emphasizing application scope rather than guild scope, and from the other app_emojis_* siblings by positioning this as the create operation.

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 provides an explicit 'When to use' section, explains that omitting application_id targets the authenticated bot application, and an explicit 'When NOT to use' section that routes guild-only emoji creation to emojis_create. This is unambiguous decision guidance.

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