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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is fully covered elsewhere. The description adds one genuinely useful behavioral fact — the output matches what the app displays today — but says nothing about the return shape (verse text? chapter/verse refs? length of the passage).

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 leading "Gita Scroller." restates the title and the second sentence is wholesale app-level marketing that does not describe this tool. Only the middle clause ("Today's reading, line by line") earns its place, so the definition is largely padding.

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 zero-required-param, read-only, no-output-schema tool the bar is low, but the agent still cannot tell what "today's reading" contains (how many verses, which chapter, what the payload looks like) or how it differs from gita_get_reading for a non-today date. Adequate but with a clear gap.

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 coverage is 100% and the single optional date parameter is fully documented in the schema (YYYY-MM-DD, defaults to today UTC). The description adds no meaning beyond that, 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 phrase "Today's reading, line by line" does name a specific resource and format, but the surrounding text ("Gita Scroller", "daily verses, plans, search and verse lookup; whole books from the Library") describes the whole app rather than this tool, making the boundary against gita_get_reading, gita_get_card and gita_list_readings fuzzy. It is not a tautology, but it is a vague framing polluted by product copy.

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 statement of when to call this versus gita_get_reading (arbitrary date) or gita_list_readings (index of readings). The mention of "plans, search and verse lookup" gestures at other capabilities without routing the agent to the sibling tools that provide them.

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