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

The readOnlyHint annotation already establishes the safe read-only nature. The description adds context about the guide's structure and the weekly data it uses, but doesn't disclose whether the tool returns a formatted guide, initiates a mode, or provides navigation. No contradiction with annotations, but more behavioral detail would be clearer.

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 sentences efficiently convey the tool's function and usage. The first sentence packs essential details about the guide's components, and the second gives a direct usage instruction. No wasted words or repetition of schema/annotations.

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 tool with no output schema, the description adequately covers what the tool does and when to use it. It could explicitly state the output format or behavior, but the description is sufficient for the tool's simple nature. The 'data of the week' phrase adds helpful context about automatic date-based input.

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 schema has zero parameters, so the description doesn't need to explain parameter syntax. The mention of 'les données de la semaine' implies the tool automatically fetches current week data, which is useful context beyond the empty schema. Baseline 4 for a no-parameter tool is appropriate.

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 identifies the tool as loading a structured parasha study guide, enumerating specific components (aliya-by-aliya, questions with commentators, haftara, Shabbat table questions). It distinguishes itself from sibling tools like sefaria_text (raw text) and sefaria_calendar (dates) by focusing on a study method.

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 final sentence explicitly states when to use the tool: whenever the user wants to prepare or study the parasha. It provides clear usage context but does not mention alternatives or exclusions, which is acceptable given the tool's specific niche.

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