emojis_create

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

Annotations already declare readOnlyHint=false, destructiveHint=false, and openWorldHint=true. The description adds the mandatory base64 data URI format, the 256KB rejection threshold, and the return shape, which are useful behavioral details. However, it doesn't explicitly mention permission requirements or what happens on failure (e.g., duplicate emoji), so it stops short of full transparency.

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 clear headers, bullet points, and an example. Every sentence adds value: purpose, usage, exclusions, example, and return info. No redundant or filler content 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?

The description covers purpose, usage context, exclusions, a concrete example, return value, and a critical size constraint. Given the tool has 5 params (3 required) and an output schema exists, the description provides sufficient context for an agent to select and invoke it correctly without ambiguity.

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%, so parameters are already documented. The description adds an example showing the exact format for guild_id, name, and image, and introduces a size limit (256KB) not present in the schema. It doesn't add much for roles or audit_reason, but the provided example and constraint meaningfully extend parameter understanding.

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 ('Upload') with a clear resource ('new custom emoji') and target ('guild'). It distinguishes from sibling tools like emojis_modify, emojis_delete, and app_emojis_create by specifying the scope (custom emoji to a guild).

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 'When to use' and 'When NOT to use' sections explicitly state use cases and alternatives, including the exact sibling tool `app_emojis_create` for application-wide emojis. It also provides a concrete constraint (image > 256KB before base64 is rejected), guiding correct invocation.

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