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

Annotations already declare readOnlyHint=true, idempotentHint=true, openWorldHint=true and destructiveHint=false, so safety and repeatability are covered. The description's real contribution is specifying the payload composition (Sanskrit + transliteration + English), which is useful and not in the structured fields. It adds no error, pagination, or bounding behavior (e.g., what happens for chapter outside 1-18).

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 first sentence duplicates the title verbatim, and the second is a run-on catalog of other features ('daily verses, plans, search and verse lookup; whole books from the Library') that does not describe this tool. Useful signal is buried rather than front-loaded; nothing here is edited for the agent's decision.

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 one-parameter read tool with full annotation coverage and full schema coverage, the description is minimally sufficient: it names the resource and the content of the return. However, it never says whether the chapter applies to the Bhagavad Gita specifically or to arbitrary books in the Library, which is a real ambiguity given the sibling set (list_books, read_book).

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 'chapter' parameter already documents range 1-18 with min/max constraints. The description adds nothing about the parameter (no defaults, no alternative identifiers like book slugs). Baseline 3 applies when the schema carries the parameter semantics.

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 first sentence describes the returned content (a whole chapter in Sanskrit with transliteration and English) but is essentially a restatement of the title rather than a specific verb+resource statement. The second sentence drifts into app-wide boilerplate (daily verses, plans, search, books) that muddles what this particular tool does. A reader can infer it fetches a chapter, but the definition never cleanly states the action.

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 guidance on when to use get_chapter versus the obvious siblings get_verse or read_book. The phrase 'read a passage at a time' hints at a granularity distinction but never resolves it, and no exclusions or prerequisites are given.

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