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

Annotations already declare readOnlyHint, idempotentHint, non-destructive and closed-world, so the safety profile is covered. The description adds one genuinely useful behavioral note, 'for voice'/'one line at a time', implying a short, chunked, voice-friendly payload, but says nothing about pagination boundaries, whether 'n' is capped, or how a missing day behaves.

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 short but not front-loaded or clean: it repeats the title verbatim and even carries the title's double period. The trailing sentence about Talmud, plans, search and whole books is scope-inflating boilerplate that does not describe this tool and dilutes the one meaningful phrase.

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?

There is no output schema, all parameters are optional and fully documented, and annotations cover safety, so the definition is minimally usable. However, with no return-value description and no routing versus sibling tools such as get_reading, an agent lacks enough context to pick this tool confidently.

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 all three parameters (n, date, reading) are fully documented in the schema with defaults. The description adds no meaning beyond that, so the baseline 3 applies.

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 opening phrase 'Today's reading one line at a time' hints at retrieving an incremental slice of a reading, but it never states the verb ('get/retrieve') or what a 'card' actually is. The second sentence drifts into a server-wide tagline about Talmud, plans, search, and the Library, which describes the whole suite rather than this tool, and it does nothing to separate get_card from siblings like get_reading or get_today.

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?

There is no when-to-use guidance, no exclusions, and no mention of the obvious alternatives (get_reading, get_today, read_book) despite the description gesturing at a broader feature set. An agent has to infer from the name alone that this is the per-line/voice variant of a reading.

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