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

Annotations already declare readOnly, idempotent, non-destructive, open-world. The description adds useful behavioral context beyond that: ordering (newest first), pagination model (one page at a time, pass last_id), and what fields are returned. It does not describe page size or rate limits, keeping it below 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?

Dense but front-loaded: purpose first, then returned fields, then pagination instruction, then sibling routing, then the endpoint. 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?

No output schema, yet the description lists the returned fields (song_id, title, duration, model, mp3 link), covers pagination, and routes to alternatives. Complete for a simple list tool.

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 baseline is 3. The description adds value on last_id by explaining the pagination loop ('Pass last_id from the answer for the next page'), slightly exceeding the schema-only baseline.

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 states a specific verb and resource ('list the songs'), notes the scope (one account, newest first, paginated), and names sibling tools it differs from (mureka_get_song for lyrics/style, mureka_list_jobs for running jobs). An agent can select it without opening the schema.

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 routing: 'For one song's lyrics and style use mureka_get_song, for jobs still running mureka_list_jobs.' This gives a concrete when-to-use-this-vs-alternatives signal.

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