update_rate

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

Annotations already convey that this is a non-read-only, idempotent, non-destructive operation. The description adds a useful behavioral detail about `rated_at` defaulting to now, but it does not disclose whether existing ratings are overwritten, what rating values are valid, or any authentication requirements.

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 description is compact and front-loaded with the core purpose, followed by the endpoint and a clean Args list. There is no redundant filler, and each line contributes useful information.

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 small four-parameter tool with an output schema and annotations, the description covers the essential parameter semantics and defaults. The main missing context is the expected rating scale/range and behavior when re-rating an already-rated item, which an agent would need for a fully correct invocation.

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 carries the full burden, and it does so well: it explains all four parameters, identifies `key` as the metadata `ratingKey`, provides a typical `identifier` example, and defines the behavior of `rated_at`. This is meaningfully informative beyond the raw schema.

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 clearly states the action, 'Rate an item,' and reinforces it with the endpoint 'PUT /:/rate'. It is distinct from the broader sibling set, though it does not explicitly call out an alternative or clarify edge cases such as updating vs. creating a rating.

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 intended usage is implied: use this tool when an item needs to be rated. However, there is no explicit guidance about when not to use it, no sibling comparison, and no prerequisites such as whether the item must already exist or whether the rating key is mandatory.

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