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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds genuinely useful domain constraints not in the annotations: TV-only from live Romanian EPG, no streaming titles. Minor overlap with the output schema in the 'Output:' sentence.

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?

Front-loads the core behavior and constraint, then usage triggers, then the sibling alternative. Dense but every clause carries signal; the quoted example phrases are slightly heavy but serve the routing function.

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?

An output schema exists, so return values need not be re-explained (though it does briefly). Domain boundaries (live EPG only), window semantics and the sibling handoff are all present. The only real gap is the three undocumented numeric/toggle parameters.

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 only 14% (just 'start'), so the description must compensate, and it names start time, duration budget, mood and channel preferences — four of seven. It leaves max_gap_min, max_segments and allow_channel_switch entirely unexplained in both description and schema.

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 (builds a plan), resource (TV watching plan), and precise scope (fills a window with one long or 2-3 consecutive programmes). It explicitly contrasts with the single-pick sibling tv_concierge, so an agent can separate the two without opening either 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?

Gives concrete trigger phrases in two languages ('plan my evening', 'ce văd toată seara', 'fă-mi un program pentru 20–24') and an explicit when-not rule (single decision that may be streaming → tv_concierge). The 3+ hour window condition is spelled out.

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