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

Annotations already declare readOnly/idempotent/non-destructive, so the safety profile is covered; the description adds genuinely useful behavior beyond that: the 7-day readability expiry, the fact that the child's name is excluded from the response, and that weak-type variantId shares the math problem-type ID space. No contradictions with the annotations.

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?

A small number of dense sentences, front-loaded with the core action and followed by the return contents, all of which earn their place given the absence of an output schema. Slightly packed, but no redundant restatement.

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?

With no output schema, the description carries the burden of describing returns and does so thoroughly, plus adds the 7-day expiry and the privacy note about the child's name. The main remaining gap is the lack of explicit guidance on when this tool applies relative to its siblings.

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 100% and there is only one parameter, so the schema already documents that url accepts either a full page URL or a 22-character ID. The description restates 'page URL or ID' without adding format or edge-case detail, which is the expected baseline when the schema does the work.

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?

States a specific verb (読む/reads) and resource (算数の学習のまとめ) and then enumerates exactly what comes back: recent grade, weak problem types with the mistaken problem text plus the child's answer and correct answer, mastered types, per-unit progress, and recent session list. This is far more than a restatement of the name and clearly separates it from siblings like find_math_problem_types or list_math_units.

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?

Usage is implied by the read-only retrieval framing and the required URL/ID, but the description never states when to reach for this tool versus the sibling analysis tools, nor any preconditions (e.g., that a summary must already exist and be within 7 days). Adequate but leaves selection to inference.

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