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

The description adds that output includes daily events ('événements du jour (Rosh Hodesh, fêtes, paracha)'), which is not in annotations. It doesn't discuss side effects, but readOnlyHint is true, so no write behavior is expected. It also doesn't contradict 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?

Two sentences, front-loaded with the primary function and followed by direction-specific instructions. No redundant content.

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 read-only conversion tool with 100% schema coverage, the description covers both directions and output events. However, it lacks explanation of 'apres_coucher' and doesn't describe output format, though these are not critical for a basic conversion.

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 description defines which parameters are relevant for each conversion direction, supplementing the schema's individual descriptions. It clarifies that 'date' is for civil-to-Hebrew and the trio 'annee_h, mois_h, jour_h' for the reverse, but omits 'apres_coucher'.

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 defines the tool as converting civil dates to Hebrew dates and vice versa ('Convertit une date civile en date hébraïque (ou l'inverse)'), including daily events. The verb and resource are specific, but it doesn't explicitly differentiate from sibling calendar tools like sefaria_calendar or zmanim.

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 instructions for both conversion directions: 'Sens civil→hébreu : passer date (YYYY-MM-DD)' and 'Sens hébreu→civil : passer annee_h, mois_h, jour_h'. This provides clear context on parameter selection, though it doesn't mention alternatives or exclusivity conditions.

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