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

Annotations already declare readOnly, non-destructive, and closed-world behavior, so safety needs no restating. The description does add real context the annotations lack: the valid 2020-2040 window and the 'Approximate' accuracy caveat. It still says nothing about result size, ordering, or pagination for a year of festivals.

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?

One tight sentence: resource, scope, return fields, valid range, and the accuracy caveat, with no filler. Everything is front-loaded.

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?

With no output schema, the description is obliged to sketch return values and does so ('name, date, rule'), and it discloses the input range and an accuracy caveat. For a simple one-parameter read tool this is close to complete; only return ordering/size is 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 description coverage is 0% and 'year' is a bare number with no documented bounds, so the description's '(2020-2040)' supplies the enforcement constraint the schema omits. It does not clarify whether the year is AD/CE or timezone-sensitive, leaving a small gap.

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 (all Hindu festivals plus sankrantis), scope ('for a year'), and the fields returned ('name, date, rule'), which an agent can distinguish from the narrower siblings festivals_in_month and next_festival. The sibling differentiation is implied by the annual scope rather than named explicitly, keeping it just short of a 5.

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?

No sentence states when to choose this over festival_details, festivals_in_month, or next_festival. The annual scope implies the use case (bulk year listing) but the agent must infer it from the sibling names.

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