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

Annotations already declare readOnly, idempotent, non-destructive behavior. The description adds genuine context beyond that: upcoming-by-default filtering and the return payload (dates, location, genres, links). It does not discuss ordering or pagination, but those are non-essential given the annotations and output schema.

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?

Two sentences with no filler. The core search purpose and default behavior are front-loaded, and every clause carries useful information for tool selection.

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 read-only search tool with an output schema, the description covers the purpose, searchable dimensions, default time filter, and returned fields. It could name the sibling difference or explain how to override the upcoming-only default, but those are minor gaps.

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 parameters are already well documented. The description adds a helpful high-level list of searchable dimensions, but it does not provide extra syntax, edge-case detail, or meaning beyond what the schema already captures.

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 verb ('search'), resource ('music festivals'), and the search dimensions (name, country, genre, month/date range). It also names the default return fields, which clearly differentiates it from sibling get_festival and search_artists.

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 implies when to use it — when searching festivals by criteria — and notes the upcoming-by-default behavior. However, it does not explicitly mention sibling tools or when-not to use it, leaving the agent to infer that get_festival is for a known festival and whats_on for nearby events.

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