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

The description says it 'sends nothing to anyone and is undone with one call, so it runs without asking first,' while the annotations declare destructiveHint=true. This directly undercuts the destructive safety signal and creates an annotation contradiction.

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?

It is front-loaded and efficient: purpose first, then behavior, permissions, and side effects. Each sentence contributes useful information without padding.

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?

The description covers purpose, permissions, side effects, and reversibility, and no output schema is needed for this tool. However, the safety conflict with destructiveHint=true leaves the invocation guidance incoherent.

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%, so all four parameters are already documented. The description only reiterates that pinned=false unpins, which the schema already states, and adds no extra parameter semantics.

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: pin or unpin a comment under a post's comments. It clearly distinguishes this from pinning posts by naming comments, so an agent can tell it apart from sibling pin_post.

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 states the pin/unpin mechanism via pinned=false and restricts use to group admins and moderators. It gives clear context but does not explicitly name alternatives or when-not conditions.

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