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

Annotations already communicate read-only, idempotent, and non-destructive behavior, so the description does not need to repeat those. It adds some context about the returned content (headliner billing, genres, origins), but does not disclose other behavioral traits such as pagination or input ambiguity handling.

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?

The description is two concise sentences: the first front-loads the purpose and content, the second gives a targeted alternative. Every sentence adds value and there is no fluff.

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 simple one-parameter read-only tool with an output schema and clear sibling differentiation, the description is complete. It covers what the tool returns, distinguishes it from the scheduling tool, and relies on annotations and schema for the remaining details.

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 100%, so the schema already fully documents the only parameter, 'festival'. The description does not add much parameter-specific meaning beyond reinforcing that the tool provides lineup information for a festival.

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 clearly states the tool's purpose: identifying who is playing a festival with the full act list, headliner billing, genres, and origins. It also distinguishes itself from a related sibling by pointing to get_set_times for day-by-day schedules, making the tool's scope easy to understand.

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 description explicitly routes the agent to get_set_times when a day-by-day schedule is needed, which provides a clear alternative condition. It does not exhaustively cover all siblings like get_festival, but the core usage context is clear.

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