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

Annotations already establish readOnly, idempotent, openWorld and non-destructive behavior, so the safety burden is largely lifted. The one genuinely new piece of context is 'for voice,' hinting the output is shaped for text-to-speech, but the description does not specify what a card actually contains or how multiple calls relate.

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 opens by restating the title almost verbatim, including a stray double period ('for voice..'), then repeats the same idea. The one useful line — 'one line at a time, for voice' — is buried inside redundant marketing prose rather than front-loaded.

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?

With no output schema, the description should characterize what a 'card' returns. 'One line at a time, for voice' gives a partial answer, but for a tool with three parameters and no output contract, the payload, ordering, and pagination semantics remain unstated.

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%: 'n', 'date' and 'reading' all carry their own descriptions and defaults. The description adds no syntax, format, or defaulting detail beyond the schema, so the baseline of 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 description conveys a resource (a daily Stoic reading 'card') and a format constraint ('one line at a time'), which distinguishes it loosely from read_book's 'a passage at a time'. However, it never clearly separates card from its closest siblings (get_today, get_reading), and the sentence is dominated by marketing copy about Marcus Aurelius, Epictetus and Seneca rather than stating the operation.

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 indication of when to use this tool versus get_today, get_reading, or read_book. The phrase 'plans, search' gestures at other capabilities but gives no condition for selecting this tool over any alternative.

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