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

Annotations already cover the read-only, idempotent, closed-world safety profile, and the description adds genuinely non-obvious behavior: results are sorted soonest-first, multi-day festivals carry an end date, and undated festivals appear separately in a verification-pending state. That last caveat is critical for an agent interpreting empty date fields correctly.

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?

Three sentences with no filler, and the core resource plus ordering are front-loaded before the verification caveat. The final sentence is long but carries high-value information about data trustworthiness, so it earns its length.

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-value documentation is not required, and annotations plus 100% parameter coverage handle the safety and argument surface. The description completes the picture with the data-verification model; only the relationship to the two sibling tools remains unaddressed.

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 coverage is 100%, so days, limit, from_date and to_date are already fully documented including defaults and ranges; the baseline of 3 applies. The description echoes the date-range scoping and ordering but adds no detail beyond the schema, such as how limit interacts with the separate undated-festival listing.

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 (Hindu festivals, vrats and observances), a scoping constraint (between two dates) and an ordering (soonest first), so an agent knows exactly what it returns. It does not, however, explicitly contrast itself with siblings get_panchang or get_vrat_guide, so differentiation must be inferred.

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?

Usage is only implied: the date-range framing suggests calendar lookups, and the mention of vrats hints at overlap with get_vrat_guide, but no when-to-use, when-not-to-use, or alternative routing is stated. With two closely related siblings, this is the definition's weakest area.

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