Rate a game

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

Annotations already provide clear safety signals: readOnlyHint false, destructiveHint false, idempotentHint true. The description adds no additional behavioral context beyond these annotations (e.g., whether it overwrites an existing rating, auth requirements, or side effects). It does not contradict annotations, but it also does not enrich the behavioral profile beyond what structured data provides.

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 two concise sentences: the first states the purpose and scale, the second adds a crucial warning. Every word earns its place; there is no fluff, and the key information is front-loaded.

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 tool with good annotations and no output schema, the description is adequate. It does not explain the return value or whether the rating is upserted, but the idempotentHint annotation covers idempotency. A short note on behavior on existing ratings would improve it, but overall it is complete enough for a tool of this complexity.

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% with both parameters well-described ('Game title, slug, or numeric Backloggd id' and '0.5 to 5, in steps of 0.5'). The description adds meaningful extra context by warning 'do not pass Backloggd's internal 1-10 value', which is not present in the schema. This clarifies the expected value domain and prevents a common mistake.

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 tool's function: 'Rate a game from 0.5 to 5 stars, in half-star steps.' It specifies both the action (rate) and the resource (a game), and the half-star detail distinguishes it from other rating-like tools. The additional note about not passing internal 1-10 values further clarifies the intended input, making the purpose unambiguous.

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 implies when to use the tool (when a star rating needs to be set) but does not explicitly mention alternatives or exclusions. Sibling tools like 'remove_rating' for deleting a rating or 'set_game_status' for status changes are not referenced. The guidance is primarily about how to use the tool (the scale) rather than when to choose it over alternatives.

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