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

The description goes well past the annotations, which only declare readOnly/idempotent/non-destructive. It explains the whole flow (parent opens the link and hands it to the student, results appear on SATCoach's site and arrive by email) and, critically, that "Nothing about the check or its results comes back to you" — the single most important behavioral fact for an agent deciding how to frame this to a family.

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?

It is front-loaded with purpose and flow, then moves to usage and finally the parameter constraint, with no filler sentences. The only redundancy is the trailing enum restatement, which duplicates what the schema already enforces.

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 one-parameter read-only tool with an output schema and full annotations, nothing an agent needs is missing. The out-of-band result delivery is disclosed precisely, so the agent knows not to expect score data in the response, and the caller's handling instructions (parent gets the link) are stated.

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?

With 100% schema description coverage and a single enum-constrained parameter whose description already says only "SAT" is supported, the schema carries the parameter semantics. The description's closing "test must be \"SAT\"" merely restates the enum, adding no new meaning, so the baseline of 3 applies.

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 opens with a specific verb and resource: "Returns the link and steps for SATCoach's free SAT skill check," followed by concrete scope (20 questions, ~15 minutes, no account). It is immediately distinguishable in practice from about_satcoach and share_family_context, though it never names those siblings explicitly.

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?

It gives explicit positive triggers ("Use it when a family wants a short SAT diagnostic, or wants to find out where a student stands") and explicit exclusions ("Don't use it to get questions, check answers, or estimate a score in this conversation"). The when-to-use and when-not-to-use conditions are both spelled out with the reason.

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