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

Annotations are empty, so the description carries the burden. It discloses the rich output (stories, quotes, cover art, visual directives, fresh stream URLs) and implies that URLs are refreshed. It doesn't cover edge cases like errors or rate limits, but for a read-only aggregation tool, it provides solid transparency.

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: the first front-loads the tool's purpose and contents, the second gives direct usage guidance. No redundant phrasing or filler; every word contributes.

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?

Given no output schema, the description enumerates the key return elements (song data, stories, quotes, cover art, visual scene directives, fresh stream URLs) and explains why it is beneficial (one call vs. many). It could mention performance trade-offs, but the core information is present.

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 100%, so the schema already documents mode, limit, and chapter_slug with descriptions. The tool description adds little beyond the 'listening mode' connection, so it relies on the schema for parameter meaning. This meets the baseline but does not exceed it.

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 uses the specific verb 'Returns' with a clear resource: 'fully curated, sequenced playlist for a listening mode', listing the exact contents (song data, stories, quotes, cover art, visual scene directives, fresh stream URLs). This distinguishes it from siblings like get_song (single track) and get_stream_url (single URL).

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 guidance: 'Use this instead of calling get_song + get_stream_url per track.' This directly tells the agent when to choose this tool over alternatives, and the 'single call' phrasing reinforces the benefit.

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