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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint, and destructiveHint=false, so safety is covered. The description adds only the granularity hint 'one line at a time' and the audience note 'for voice'; it says nothing about pagination across cards, how n interacts with the reading, or what is returned.

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 text is short but poorly structured: it duplicates the title verbatim, contains a doubled period ('voice..'), and appends a server-level capability list that belongs elsewhere. The useful scoping information is not front-loaded ahead of the noise.

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 tool with no output schema and full schema coverage, the description should clarify the core concept ('card', one line at a time) and its relationship to the reading/plan parameters. Instead it leaves 'card' undefined and spends its budget on unrelated server features, so an agent cannot confidently distinguish it from get_today or get_reading.

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 documented in the schema with defaults and formats. The description adds no syntax or semantics 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 description opens by repeating the title verbatim ("Today's reading one line at a time, for voice"), which is a tautology rather than an explanation of what a 'card' is. The trailing clause ('Bhagavad Gita: daily verses, plans, search and verse lookup; whole books from the Library...') describes the whole server's feature set, mapping to siblings like search_readings, get_verse, and read_book rather than this tool, so it fails to distinguish get_card from its siblings.

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, when-not-to-use, or alternative-tool guidance. The description does not explain how get_card relates to get_today, get_reading, or get_chapter, and the server-wide feature blurb actively muddies the choice by implying search and book-reading capabilities.

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