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

Annotations already declare 'readOnlyHint: true', so the description does not need to stress safety. The description adds helpful behavior details (interactive layout, French default language fallback logic) beyond that annotation. However, it does not disclose potential rate limits, network dependencies, or what happens if the daf is not available. With annotations covering the safety profile, a 3 is appropriate.

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?

The description is two front-loaded sentences with zero waste. The first sentence states core function and features; the second covers defaults and usage examples. Every word earns its place.

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?

Given the simplicity (2 optional parameters, no output schema, no nesting, high schema coverage) and the readOnly annotation, the description is complete. It explains default behavior, optional language constraint, and usage intent. No gaps for an agent to misinterpret.

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%, so the baseline is 3. The description adds context about the default behavior (daf yomi) but does not explain the 'ref' parameter syntax or the language fallback logic in more depth than the schema. It does not compensate for the schema's simple descriptions, thus stays at baseline.

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 uses specific verbs ('Affiche', 'montre-moi', 'ouvre') and a clear resource ('page de Guemara en visualiseur interactif façon Vilna'). It distinguishes the tool's scope from siblings like 'sefaria_links' or 'sefaria_text' by describing its unique interactive features (texte au centre, Rachi et Tossafot dépliables, traduction au clic). The default behavior (daf yomi du jour) is also specified.

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 description explicitly states when to use this tool: 'dès que l'utilisateur veut VOIR ou étudier un daf'. It provides concrete usage examples ('montre-moi le daf du jour', 'ouvre Berakhot 2a'). While it does not explicitly say when NOT to use it, the purpose is so clearly scoped to 'voir/étudier un daf' that alternatives are effectively excluded, and the sibling list shows other tools for other needs (e.g., 'sefaria_search' for general searching, 'mode_etude' for study mode).

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