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

Annotations declare the safety profile (non-readonly, idempotent, non-destructive), and the description adds real value beyond them: it discloses that the call posts a 'rated' update to the feed and that the first invocation is a no-op preview requiring re-invocation with confirm_token. It also clarifies that 0 clears the rating, an important semantic not evident from 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?

Front-loads the core action, then the domain constraint, then the side effect, then the two-step protocol. Every clause earns its place with no redundancy against the schema.

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?

With no output schema, the description does the right thing by describing the first-call return (preview plus confirm_token). For a mutation tool with solid annotation coverage, this is nearly complete, though it does not address error or failure behavior.

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 67% and the schema already encodes the numeric bounds (min 0, max 5, multipleOf 0.25) and describes both confirm_token and bottle_id. The description still contributes meaning by explaining that a 0 rating clears the value rather than setting a low score, which the schema cannot express.

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+resource ('Rate one of your bottles'), and adds the exact domain range (0-5 in 0.25 steps, 0 clears), which distinguishes it from siblings like update_bottle or set_bottle_status. An agent can identify the operation without opening the schema.

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?

Provides strong procedural guidance with the explicit two-step preview/confirm protocol (show preview, then repeat with confirm_token). It does not, however, name alternatives such as update_bottle or set_bottle_status or state when this tool is preferable.

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