Rate item

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

Annotations already declare the operation non-read-only, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds the useful detail that the target is the *owner's* rating (not an aggregate) and that null clears it, but says nothing about auth requirements, response behavior, or what happens if ratingKey is invalid.

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 front-loaded sentence that carries the value range, the clear sentinel, and the target of the operation with zero filler.

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 mutation with no output schema, the description covers the rating semantics but omits what `ratingKey` is and what the call returns or does on failure. Adequate but with a clear gap on the identifier parameter.

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 0%, so the description must compensate. It does explain the `rating` parameter's semantics (0-10 range, null to clear), but `ratingKey` is never explained — the schema only reveals a numeric-string pattern, not that it identifies the item. An agent is left guessing what this required key refers to.

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 pair (set/clear) and resource (owner's rating on an item), with the value range and the null-clears semantics. No other rating tool exists among the siblings, so no explicit differentiation is needed, but the description also doesn't tell the agent how this relates to the many item-scoped siblings.

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?

Usage is only implied: an agent can infer it should call this to assign or remove a rating, but there is no explicit when-to-use, no prerequisite (e.g. must be the owner or authenticated user), and no note about how it interacts with set_watched or other item mutations.

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