validate_playlist

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

Annotations already establish that this is a safe read (readOnlyHint=true, destructiveHint=false), and the description adds substantive behavior the annotations cannot convey: violation records carry track ids and a signed adjust_by in the constraint's unit, duration violations also carry adjust_by_display, and target_energy is scored rather than enforced. It also warns that energy is estimated and must be disclosed, which is a real behavioral constraint on downstream answers.

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 most important directive (what the tool does, and call it before presenting) is front-loaded, and every subsequent paragraph carries a distinct instruction: adjust_by semantics, verbatim quoting rules, cross-tool bound reuse, and energy caveat. It is on the long side for a nine-parameter tool, but no sentence is redundant.

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 has to sketch the return shape and it does: violations, adjust_by, adjust_by_display, soft_scores, track_count, total_duration_display. The remaining gap is the unmentioned constraint parameters, which an agent must guess from their names alone.

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 description carries the full burden. It explains target_energy well (0-1 range, scored not enforced, soft_scores output) and gives intent for released_after/released_before by tying them to check_feasibility, but required_genres, max_total_duration_ms versus min_total_duration_ms, max_track_duration_ms, and max_tracks_per_artist are never mentioned — half the parameters remain opaque.

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 and resource (check a proposed playlist against hard constraints) plus the scope of the output (report every violation). It implicitly separates itself from check_feasibility by instructing the caller to reuse the release-year bounds given to that sibling, so an agent can tell the two apart.

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?

Explicit temporal gating ('Call this before presenting any playlist', 'Do not judge for yourself'), an explicit cross-tool dependency ('Pass the same release-year bounds you gave check_feasibility'), and an explicit conditional trigger ('If the user asks for an energy level or a mood, pass target_energy'). Nothing is left to inference.

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