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

Annotations already indicate a destructive, non-idempotent operation, and the description adds meaningful context beyond that: the 'three flags hide it pending moderation' threshold and the moderation workflow. This gives the agent a concrete sense of the tool's side effects without contradicting the annotations.

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?

The entire description is one compact sentence that front-loads the action and purpose, then adds the key moderation consequence. No words are 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 simple two-parameter tool with no output schema, the description covers the operation, the reason categories, and the behavioral outcome. It doesn't describe the exact response shape, but that is a minor gap given the tool's simplicity.

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, but the description enriches the otherwise minimal 'reason' schema entry by listing example flag types ('spam, unsafe, coordination'). This helps the agent choose an appropriate reason value.

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 uses a specific verb ('Flag') with a clear resource ('a post') and purpose ('for review'), and identifies the relevant flag categories. It also states the moderation consequence, making it clearly distinguishable from sibling tools like board_post and board_read_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?

The description provides clear context for when to use this tool: when a post needs flagging for spam, unsafe content, or coordination. It doesn't explicitly name alternative tools or exclusion criteria, so it falls short of the top score, but the intent is unambiguous.

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