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

Annotations already declare readOnlyHint=false, destructiveHint=true and idempotentHint=true, so the safety profile is covered. The description adds genuine context beyond them: it explains that an empty string is the clearing mechanism (the concrete destructive behavior) and that the change has no downstream delivery side effects. It omits any permission/auth requirements, which keeps it from a 5.

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?

Two tight clauses with no wasted words, and the clearing behavior is front-loaded. The shorthand 'nothing re-delivers' is slightly cryptic out of context, which is the only thing keeping it from a 5.

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?

An output schema exists, so return values need not be described, and annotations carry the safety profile. However, for a 2-required-parameter mutation the description leaves connectionId entirely unexplained and offers no pointer to how an agent resolves a connection. Adequate but with a visible gap.

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 50%: 'label' is already documented as 'New label; empty string clears it', which the description merely repeats, while 'connectionId' is undocumented in both places. The phrase 'connected Discord channel' gives only a faint hint that connectionId identifies that channel. With half the parameters carrying no semantic explanation anywhere, the description does not fully compensate.

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 ('Set the display label') and a precise resource ('a connected Discord channel'), which cleanly distinguishes it from the sibling rename tools (rename_form, rename_project, rename_workspace). The added parenthetical clarifies the edge case of clearing. It stops short of explicitly contrasting itself with any sibling, so it is clear but not fully differentiated in-text.

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 says what the tool does but never states when to use it versus alternatives, nor any prerequisite (e.g. the channel must already be connected/selected via fillo_select_connection). 'Nothing re-delivers' is a scoping remark, not usage guidance. An agent gets no explicit when/when-not signal.

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