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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so safety is covered. The description adds genuinely new behavioral context the annotations cannot express: an authorization gate and the resulting error for non-API-key callers. It stops short of covering pagination or result shape, so a 4 rather than 5.

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, zero filler. The capability statement comes first and the access restriction second, which is the right order since the restriction is a gating condition rather than the primary purpose.

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?

No output schema exists, but the description signals what comes back ("with their results") and fully covers the unusual access model, which is the main risk for this tool. Only minor gaps remain, such as ordering or pagination behavior, so it is nearly complete.

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% for the single limit parameter (max 50, default 10), so the schema carries the full burden. The description adds no meaning beyond it, which matches the baseline 3 for a fully documented parameter set.

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 ("List recent screenings") plus what is returned ("with their results"). The clause about looking screenings up by report id implicitly distinguishes it from get_screening, so an agent can route without opening sibling schemas.

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?

Explicitly states the access condition ("only available to the MusicCheck service API key"), the failure mode for other callers ("accounts signed in through Claude receive an error"), and the alternative path ("look up screenings by report id"). This is a full when-to-use / when-not-to-use / alternative triad.

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