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

Annotations already cover the safety profile (readOnly, non-destructive, closed-world). The description adds genuinely non-obvious behavioral context beyond that: the verse is globally shared per day and keyed to India time, which an agent could not infer from the schema. It does not describe the return shape, but no output schema exists to cover that either.

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?

Two tight sentences with no filler; the usage trigger is front-loaded. The timezone qualifier is slightly buried at the end but it is short and earns its place.

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 no-parameter, read-only lookup with no output schema, the description covers what the agent needs to select and call it. The only mild gap is the absence of any hint about the response content, which the missing output schema would otherwise supply.

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?

The tool takes zero parameters, so there is nothing for the description to clarify and the baseline of 4 applies. Schema coverage is 100% trivially.

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?

States a specific resource (the Bhagavad Gita daily verse) with a clear retrieval verb and scope. The 'today's verse' framing distinguishes it from sibling get_gita_verse (a specific verse) and search_gita (a search).

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?

Explicitly names the triggering conditions ('today's verse', 'a daily verse', 'a random verse'), which is strong when-to-use guidance. It does not explicitly name the alternatives (e.g., use get_gita_verse for a specific chapter/verse), so it stops short of a full routing statement.

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