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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), so the bar is lower. The description adds the seven-day cap and the medical exclusion, which is useful scoping context, but says nothing about output shape, ranking criteria weighting, or why a window might be rejected.

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, and the ranking scope is front-loaded ahead of the exclusion. Slightly under-specified rather than padded, which is preferable to verbosity.

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?

An output schema exists, so return values need not be explained, and the annotations carry the safety profile. But for a 10-parameter tool with nested objects, a 30% schema coverage rate, and a required natal chart plus location duality, the description leaves too much of the invocation contract undocumented.

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 30% across 10 parameters, including a nested natal object with its own anyOf location requirement, so the description must compensate and it does not. None of activity, startDate/endDate, limit, or the place/coordinates duality is explained in the text.

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 concrete verb (Ranks) and a bounded resource (a maximum seven-day range) and names the techniques applied (Panchanga, prohibited intervals, Tara Bala, Chandra Bala). It does not explicitly contrast itself with the sibling find_muhurta, so the 'natal fit' distinction is left to the tool name.

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 exclusion 'Medical procedures are unsupported' is a genuine when-not constraint, reinforced by the activity enum lacking a medical option. However, there is no guidance on when to pick this over find_muhurta or find_marriage_windows, so selection between near-identical siblings is left to inference.

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