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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint and destructiveHint=false, so the safety profile is covered structurally. The description adds only that the output is line-by-line and mirrors the app's current-day view, which is modest but real return-shape context; it says nothing about caching, date handling edge cases, or fallback when no reading exists.

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 body repeats the title nearly verbatim ('Today's reading, line by line (same as the app shows today)'), which is pure duplication. The second sentence is a broad app-capability blurb covering features this tool does not expose, adding length without adding selection signal.

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-parameter read tool with full annotation coverage and high schema coverage, the description supplies the essential fact that output is a line-by-line today view. It omits anything about empty-day behavior or how the 'today' boundary is computed beyond the schema's UTC note, leaving it merely adequate.

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% and the single 'date' parameter (optional, YYYY-MM-DD, defaults to today UTC) is fully documented in the schema. The description adds no formatting, timezone nuance, or past/future-date guidance beyond it, 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 states a concrete verb and resource: retrieve today's Gurbani reading, presented line by line, matching what the app shows today. That is clear enough for an agent to know what comes back. It does not, however, distinguish itself from close siblings such as gurbani_get_reading, gurbani_get_card or gurbani_list_readings, so it stays 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?

There is no statement of when to choose this tool over gurbani_get_reading (a specific reading) or gurbani_get_card. The trailing sentence enumerates app features ('plans, search, Ang and shabad lookup; whole books') without tying any of them to a selection condition for this tool.

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