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

Annotations already declare readOnlyHint, idempotentHint, and non-destructive, so the safety profile is covered. The description adds genuinely new behavior: the ticket lifetime (15 minutes), the consuming client (the studio in the chat), and the downstream actions it enables. No contradiction with the read-only/idempotent 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?

Two sentences, front-loaded with the return value and terminating on the actionable routing instruction. The middle clause is compound (three separate studio uses) but each clause carries information; nothing is 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 carries return-value explanation and does so at a useful level (a 15-minute ticket, not a session object). Combined with annotations covering safety and a fully documented single parameter, an agent has what it needs, though the ticket's form/consumption contract is left implicit.

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?

There is a single parameter and schema description coverage is 100%, with songId already documented as coming from list_songs or create_song. The description adds no syntax or constraint detail beyond that, so the 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 states a concrete outcome: returning a 15-minute ticket for one of the person's songs, plus what the studio does with it (upload stems, label check, progress, playback). It is clear on its own, but it never distinguishes itself from the similarly named sibling open_song_studio, and the name/title mismatch ('get' vs 'Start a session') leaves residual ambiguity about the verb.

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?

It gives an explicit when-not: 'The studio calls this tool on its own; the assistant does not need to call it directly,' which is exactly the routing signal an agent needs. It does not name an alternative for cases where the assistant does need a session (e.g. open_song_studio), so it stops short of full when/alternative coverage.

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