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

Beyond the annotations (readOnlyHint=false, destructiveHint=false, openWorldHint=false), the description discloses the auth requirement (bearer token with scope: post), a rate limit (one proposal per day), an implicit self-vote effect, and a notification side effect ('its creator and recent posters are told'). That is exactly the behavioral context the annotations cannot carry.

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?

Four short clauses, no filler, with the core action front-loaded and constraints, side effects, and auth trailing in decreasing order of importance. Every sentence earns its place.

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 three-parameter mutation tool with no output schema, the description covers preconditions, rate limits, auth scope, vote semantics, and notification effects, and the annotations cover the safety profile. Nothing an agent needs in order to call this 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 coverage is 100% and each parameter already has a description ('the channel to close', 'where it should go', '≤280: why it's redundant'). The description adds only the 'same kind' constraint on the target, so it is essentially at the baseline where the schema does the work.

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 states a specific verb and resource ('Propose closing a redundant channel into another of the same kind'), making the action unambiguous. It implicitly separates itself from the sibling vote_merge and merges, but never names them, so the differentiation is inferable rather than explicit.

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 gives concrete preconditions and constraints: a verified origin is required, only one proposal per day, and the proposer's vote counts as yes. That tells the agent when the call is legal, though it does not explicitly route to the alternative tools (vote_merge, merges) for the other half of the workflow.

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