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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, covering safety and non-mutation traits. The description adds the 'random' nature and optional filters, which is useful. However, it does not disclose the return format, pagination, or potential limitations (e.g., if filters are invalid). Given the annotations carry the safety burden, this is a moderate contribution.

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 description is a single, front-loaded sentence that states the primary action first, then adds the optional filters. It is efficient with no redundant wording, making it easy to parse quickly.

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 simple random-text tool with no output schema, the description covers the essential function and parameter usage. However, it does not address how to differentiate this from related tools like get_random_source_by_topic, nor does it describe the expected output structure (e.g., passage text with reference). The presence of many siblings increases the need for clearer differentiation.

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 only 33% (vowels is described). The description compensates for titles and categories by explaining their meaning with concrete examples (e.g., categories ['Tanakh'], titles ['Psalms', 'Proverbs']). It does not fully specify valid values or interaction rules between parameters, but it does add meaningful context beyond the bare schema.

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 clearly states the tool's function: 'Get a random passage' with optional filtering by books or categories. It uses a specific verb and resource, and provides examples of valid filter values. While it doesn't explicitly differentiate from sibling tools like get_random_source_by_topic, the core purpose is unambiguous.

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?

The description offers no guidance on when to use this tool versus alternatives, nor does it specify any conditions or exclusions. The example of categories and titles is more about parameter format than usage context. An agent has to infer when this tool is appropriate rather than being told.

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