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

Annotations already declare readOnlyHint=true and openWorldHint=false. The description adds the 48-hour time window and that reflections are filtered to one song when songSlug is provided – useful behavioral context beyond the annotations.

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?

A single sentence that front-loads the two return modes and then their conditions. It is efficient, though the poetic phrasing ('reflections others have left') slightly reduces immediate clarity.

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, and the description does not explain the shape of the returned data (e.g., list of song objects or reflection text). Annotations cover safety, but the description leaves return-format details to inference.

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 descriptions cover songSlug and timezone, but not the required 'what' enum. The description clarifies 'what' by mapping songs to the last 48 hours and reflections to a scoped list, and explains songSlug's effect as a filter. It adds meaning beyond the 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 it returns a catalog of songs or reflections, with the 48-hour window and songSlug scoping. It does not distinguish itself from siblings like read_song or reflect, so it stops just short of full clarity.

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?

Offers no explicit when-to-use or when-not-to-use guidance against alternatives. The only conditional is for the songSlug parameter, not for tool selection. Sibling tools are never mentioned.

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