library_report

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

Annotations already declare readOnlyHint=true and openWorldHint=false, and the description's "Read-only: it never deletes anything" largely restates that safety profile. It does add one useful clarification for a cleanup-oriented tool: the deletion candidates it surfaces are advisory only and nothing is removed. No mention of cost, pagination, or output shape, so it is adequate but not rich.

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 report contents are front-loaded in one dense sentence, followed by the read-only guarantee and two short example queries. Every line earns its place, though the section enumeration is long enough to read as a list rather than a summary.

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 explained, and the description covers the report's coverage well. The only real hole is the undocumented `limit` parameter, which matters for interpreting "biggest series/movies".

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 50%: the schema documents `service` but `limit` has only a default and min/max bounds with no stated meaning. The description never mentions `limit` or its role (top-N of the biggest series/movies), so the ambiguity around what "biggest" returns is not resolved by prose.

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 names a specific deliverable (a disk-usage/cleanup report) and enumerates its sections: total size, biggest series/movies, unmonitored items with files, completed ended series, size per quality, free space per root folder. That enumeration implicitly separates it from raw-infrastructure siblings like get_disk_space, but no sibling is named explicitly, so it stops short of a 5.

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?

Usage is conveyed only through example questions ("What takes the most space?", "What could I delete to free space?"), which implies the right context without stating when to prefer this over get_disk_space or search_library. There are no exclusions or prerequisites given, so guidance is implied rather than explicit.

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