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

Annotations already declare readOnlyHint=false and destructiveHint=false, so mutation semantics are covered. The description adds genuinely useful context beyond that — the spark cost and the once-per-day throttle — but says nothing about what happens on failure or whether reviews can be edited afterward.

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?

Two short sentences, front-loaded with the action and followed by the cost/rate constraint. No wasted wording, and both sentences carry information an agent needs.

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 non-idempotent write tool with no output schema but full annotation coverage, the description supplies cost, frequency, and content expectations. Only minor gaps remain, such as return behavior and the undefined 'sparks' unit.

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: the schema documents all four parameters including ranges and the api_key example. The description adds guidance for the `text` content ('what you would order and why') and implies brevity, but the `stars` field explicitly defers to the tool description for meaning, which the description never supplies.

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 states a specific verb and resource: 'Write a short review of a restaurant', and even names the content expected ('what you would order and why'). It does not explicitly differentiate from siblings such as list_restaurants, but the write-vs-list distinction is obvious from the verb.

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?

'2 sparks, once a day' implies cost and frequency constraints, which shape when an agent should invoke this. However, there is no explicit statement of when to use this versus alternatives, or preconditions such as needing a valid restaurant id from list_restaurants.

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