discord_set_guild_icon

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

Beyond the annotations (which only say non-read-only, non-destructive, idempotent, open-world), the description adds the Manage Server permission requirement, the accepted image formats, the 10 MB rejection threshold, and the return value. These are exactly the failure modes an agent needs to avoid a rejected call.

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?

Purpose is front-loaded, followed by disambiguation, then input constraints, then return value — a sensible order with no filler. The format/size sentence partially duplicates the image parameter's schema description, which is the only wasted text.

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?

Covers purpose, the sibling it is confused with, permissions, input encoding options, validation limits, and the return value; an output schema also exists so return details are already backed. Nothing an agent needs to invoke this mutation correctly is missing.

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% and the image parameter already documents the https URL / data URI / bare base64 forms and the format and size limits, so the description largely restates schema content. No additional semantics are added for guild_id or the audit-log reason parameter.

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?

States a specific verb and resource ('Replace the server's icon') and immediately disambiguates which icon by naming the sibling that changes a different one (discord_set_bot_avatar). An agent can distinguish it from discord_remove_guild_icon or discord_set_guild_banner without opening any 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?

Explicitly names the alternative tool for the bot avatar and states the permission prerequisite, which frames when this tool is the right choice. It does not explicitly point at discord_remove_guild_icon for the inverse operation, so it stops short of full when/when-not routing.

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