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

Annotations already declare read-only, idempotent, closed-world and non-destructive, so the safety profile is covered. The description still adds real context beyond that: the upstream data source and its English-edition provenance, the default date window (today to 30 days), and the shape of what comes back including Korean titles and a festivaltimes.net URL.

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 dense paragraph with the scope front-loaded, then filtering, then return shape. No sentence is filler.

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 carries the return-value burden and does so by listing the fields returned. Minor residual gaps: no mention of result ordering, and limit behavior lives only in the schema.

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 a 3 is the floor, and the description earns above it by explaining that the keyword matches title, performer and venue, and that from/to default to today through 30 days out — neither of which the schema states.

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?

Names a specific verb and resource (search popular-music concerts) and pins the scope tightly: South Korea, KOPIS data via the Festival Times English edition. An agent can tell it apart from search_festivals or festivals_this_weekend without opening a schema.

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 implied rather than stated: 'popular-music concerts' vs the festival siblings is an implicit carve-out, and the default date window signals a sensible no-arg call. But no sibling is named as an alternative and there are no explicit when-not conditions.

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