discord_set_bot_guild_avatar

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

Goes well beyond the annotations by disclosing the server-side prerequisite ('Requires the server to have the BANNER or ROLE_ICONS-adjacent boost feature set') and that Discord rejects the call without it, which an agent cannot infer from readOnlyHint/idempotentHint. The prerequisite phrasing is hedged and imprecise ('-adjacent'), which softens an otherwise strong disclosure.

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?

Front-loaded with the core action and the scope override, then prerequisites, then input formats and reset semantics. Every sentence carries information, but the prerequisite clause is wordy and slightly obscure for what it conveys.

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 action, prerequisite, accepted input forms, reset behavior and return value, which is more than enough for a 3-parameter mutation with a full schema and an output schema. The only gap is that the boost prerequisite is described imprecisely, so an agent may not know exactly how to verify eligibility.

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 the baseline is 3. The description adds the consequence the schema omits: null does not merely clear, it falls back to the global avatar, and the accepted image forms are restated as a coherent input contract. Marginal but real value on top of the schema.

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 ('Set the bot's per-server avatar') and immediately defines the scope distinction that matters: it overrides the global avatar in one server only. That separates it cleanly from discord_set_bot_avatar without the agent needing to open either 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?

Gives clear conditions for use (per-server override vs global fallback) and an explicit reset path ('Pass null to clear it and fall back to the global avatar'). It does not name discord_set_bot_avatar directly as the alternative, so the routing is implied rather than stated.

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