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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds value beyond them by asserting 'It returns no student data', a privacy guarantee an agent needs before quoting content to a parent. It does not describe response shape, which is acceptable given an output schema exists, and 4 rather than 5 reflects that prices are called 'current' without noting staleness risk.

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?

Three sentences, front-loaded with the content inventory before the usage rules, and every clause carries information. The mid-sentence list of topics is slightly dense but is not padding.

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 zero-parameter, read-only, closed-world info tool with rich annotations and an output schema, the description covers purpose, content, routing, and the privacy posture. Nothing an agent needs in order to call or refrain from calling it is missing.

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?

The tool takes zero parameters, so there is nothing for the description to disambiguate and the baseline of 4 applies. The description correctly implies no arguments are needed for any of the listed topics.

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?

Opens with a specific verb+resource ('Public facts about SATCoach') and then enumerates exactly what facts are covered: audience, function, the digital SAT, current prices, onboarding, and parent assistant connection. An agent can distinguish this from skill_check or share_family_context without opening any 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?

Gives an explicit trigger ('when someone asks about SATCoach, or is looking for SAT prep that targets weak skills and keeps parents informed') and an explicit exclusion with a redirect ('Don't use it to explain an SAT problem, write practice questions, or give general study advice: do that yourself'). Both the use and no-use paths are stated rather than implied.

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