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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds useful behavioral detail beyond annotations: it is a pure reference endpoint, requires no plot, cites verses per row, and labels elements as a later convention. This helps an agent know what kind of response and content to expect without contradicting the annotations.

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 three sentences and front-loads the core purpose and content of the endpoint. Each sentence contributes meaningful information: content, intended use, and provenance labeling. It is slightly dense but remains appropriately sized for the richness of the reference data it describes.

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?

The description is complete for a simple read-only reference endpoint: it explains what fields rows contain, confirms no plot is needed, and provides the intended use case. The input schema covers pagination and localization, and annotations cover safety. With no output schema, the description partially compensates by listing the meaningful data elements, though it does not describe exact response shape.

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%, so all four parameters are fully documented in the input schema itself. The description does not add parameter-level detail, but it does not need to because the schema already explains lang, limit, offset, and compact with defaults and examples.

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 defines the tool as a reference table of the eight Vastu directions and enumerates exactly what each row contains: dikpala, mandala squares, devatas, chapter placement, and water effects. It also separates this from plot-related endpoints by calling it a 'pure reference endpoint with no plot required.' This makes its purpose and scope 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 gives clear use cases: 'for building a picker or a directions guide.' It also implies when not to use it by saying 'no plot required,' distinguishing it from the post_vastu_plot family. It does not explicitly name alternatives or list exclusion conditions, but the context is sufficient for an agent to choose effectively.

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