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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is covered. The description adds the useful behavioral detail that the call returns a rule explanation alongside the date, but says nothing about lookup failure behavior when a name is unknown.

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?

A single tightly packed sentence with no filler and the resource front-loaded ahead of the two required qualifiers. It is borderline telegraphic ('Date + rule explanation'), but nothing redundant is included.

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 two-parameter read-only lookup with no output schema, the description covers purpose, inputs, and the shape of the result (date + rule explanation). The main missing piece is disambiguation from the three sibling festival tools.

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%, so the schema itself documents neither parameter. The description partially compensates by tying 'name' to the festival identity and 'year' to the lookup year, but it adds no format hints (e.g. whether name is canonical/id or accepts aliases, or year bounds).

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 names a specific resource (one festival) and the exact payload (date plus rule explanation) scoped by name and year, which is more precise than the bare title 'Festival details'. It does not explicitly contrast itself with the sibling lookups (list_festivals, next_festival, festivals_in_month), so it stops 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?

There is no stated when-to-use or when-not-to-use guidance, and no sibling is named even though three nearby tools cover overlapping festival lookups. The implicit scoping ('one festival by name in a year') hints at the single-record use case but leaves routing to inference.

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