app_emojis_modify

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

Annotations already establish write, non-destructive, idempotent behavior; the description adds the key constraint that emoji image bytes cannot be edited and outlines the replacement workflow. It also states the return shape. It does not cover edge cases like rate limits or permission requirements, but annotations cover the main safety profile.

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 organized into Purpose, When to use, When NOT to use, and Returns sections with no filler. Every sentence contributes routing or behavioral information.

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 tool with full schema coverage, an output schema, and rich annotations, the description provides the necessary operation scope, the main limitation (no byte editing), and the replacement path. It is sufficient for an agent to call the tool correctly, though it does not discuss authorization or error conditions.

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 covers 100% of parameters with descriptions and validation patterns. The description adds no significant parameter semantics beyond the schema; it restates the `application_id` default behavior already present in the schema. Baseline 3 is appropriate.

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 clear verb+resource: 'Rename an application emoji.' This distinguishes it from the guild-oriented sibling `emojis_modify` and identifies the exact operation in one sentence.

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 provides explicit 'When to use' bullets, including the optional `application_id` behavior, and a 'When NOT to use' bullet that names `app_emojis_create` and `app_emojis_delete` as alternatives for byte replacement. An agent can route correctly without inference.

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