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

Annotations cover the read-only and open-world profile, so the bar is lower, and the description adds a genuinely non-obvious behavioral constraint: audio is unavailable, only text metadata and a link are returned. This prevents the agent from promising playback. It doesn't mention ordering, caching, or freshness of tracks, which keeps it from a 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, front-loaded with what the tool returns and followed by the key constraint plus presentation instruction. The field enumeration is dense but each item earns its place since there is no output schema. No filler.

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 must convey return shape, and it does so thoroughly by listing every field. It is also explicit that audio is not returned. The only minor gap is omission of result ordering and whether tracks are paginated or capped, but for a 1-parameter read tool this is close to 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%, and the single 'limit' parameter already documents its default of 5 and maximum of 20. The description adds nothing about the limit, so the schema carries the full load — baseline 3 applies.

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 the resource concretely (songs generated by Orb Studio from its news radars) and enumerates returned fields — title, style, mood, BPM, topics, lyrics, cover, listen link. It stops short of an explicit retrieval verb like 'list' or 'fetch', but an agent can tell immediately this returns track metadata. No sibling tool overlaps with music, so differentiation is moot.

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?

The second sentence gives actionable handling guidance — 'You cannot hear the audio; use the text to describe a track and give listen_url' — which shapes how the agent presents results. However, it never states when to call this tool (e.g., when the user asks about Orb Studio songs or news-radar music) or any exclusions. Usage is implied from the domain rather than stated.

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