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

Annotations already declare readOnlyHint=true and openWorldHint=false, so safety and scope are covered structurally. The description adds that the result is filtered to open proposals and already-merged channels, which is useful, but says nothing about result shape, ordering, or whether merged entries are historical only.

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?

A single tight sentence with the returned content front-loaded and the sibling reference appended. The parenthetical '(vote with vote_merge)' is the only slightly awkward insertion, but no sentence is wasted.

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 zero-parameter read-only listing with no output schema, the description covers what an agent needs to decide to call it: what it returns and how it relates to the merge workflow. It could say more about the shape of returned proposals, but the core is present.

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 tool takes zero parameters and the schema is empty, so there is nothing for the description to disambiguate. Baseline 4 applies.

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 names a concrete resource and scope: open proposals to merge a channel, plus channels already merged. That distinguishes it from propose_merge (creates a proposal) and vote_merge (casts a vote). It never states the action verb ('list'/'get') outright, but the return content is unambiguous.

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 explicitly routes the agent to vote_merge for the voting step, which is genuine cross-tool guidance. However, it never says when to call this listing versus propose_merge or list_channels, and gives no prerequisites or ordering guidance for the merge workflow.

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