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

The annotations already mark the tool as read-only. The description adds meaningful behavioral context beyond that: it names the data source (Hebcal), the specific computed outputs (alot, netz, sof zman, shkia, tzeit, etc.), and the mode switch triggered by chabbat=true. This goes beyond what annotations alone convey, though it does not discuss error behavior or formatting.

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 compact and front-loaded: it leads with the core output list, then explains the key mode switch, data source, and location options in three short sentences. Every sentence contributes distinct information, and there is no fluff or repetition of the tool name.

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 that there is no output schema and seven parameters, the description carries the burden of explaining what results the tool produces and how to select them. It lists the zmanim categories, the Shabbat/paracha mode, the data source, and the two location input styles. It is reasonably complete for a read-only lookup tool, though it could have briefly mentioned timezone handling or result format.

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 71%, and the description adds real semantic value: it clarifies that the default behavior is for 'today', that chabbat=true changes the result set, and that latitude/longitude are 'free coordinates'. It reinforces the city-vs-coordinates distinction that the schema partially conveys. It does not mention tzid or geonameid, but those are already documented in the schema.

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 returning daily Jewish prayer times (zmanim) and, optionally, Shabbat entry/exit times and the weekly parasha. It names the specific resource and content types, making the purpose obvious. It does not explicitly contrast itself with sibling tools like sefaria_calendar or guide_paracha, so it stops short of a 5.

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 gives clear usage context: it covers daily zmanim by default, and explicitly explains that setting chabbat=true switches to Shabbat times and parasha. It also describes the two location modes—predefined cities or free coordinates. It does not explicitly state when to prefer this tool over alternatives, but the conditional behavior is clear enough for correct invocation.

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