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

Annotations already declare readOnlyHint=true and destructiveHint=false, so safety is covered; the description adds genuinely non-obvious behavior: stem FLAC links appear only a few seconds after the mix, and kind "sfx" songs never have stems. Those timing and conditional-output facts materially change how an agent should poll and interpret empty fields. It does not describe behavior for pending/failed songs or nonexistent ids, which keeps it below 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?

It is a single dense sentence with essentially no filler, and the core idea (where the song stands) is front-loaded before the enumeration of returned links. The nested 'or, once done, ...' clause is somewhat convoluted to parse, costing it a point, but nothing is redundant.

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 the burden of describing return values and does so in detail — queue position, per-version links, stem links, sfx exception. What is missing is minor but real: no mention of non-success states (failure, cancellation) or error handling for invalid ids.

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% and the single id parameter is already fully documented in the schema (pattern plus 'the song's id from create_song'), including where to obtain it. The description adds no further parameter semantics, 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 names the resource (a song created by create_song) and precisely enumerates what the response contains: queue position, per-version MP3/WAV links, five stems' FLAC links, and in-progress redo_stem parts. It is a status/read tool stated as a noun phrase rather than an explicit verb, so it reads slightly as an inventory of returns rather than 'check the status of', but the resource and scope are unmistakable. Sibling differentiation is partial: it references create_song and redo_stem but never contrasts itself with list_songs or get_songs_left.

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?

Usage is only implied — the phrase 'Where a song made with create_song stands' tells the agent this is the post-creation polling tool, and mentioning redo_stem hints at checking redo progress. There is no explicit instruction on when to prefer this over list_songs (bulk listing) or get_songs_left (remaining count), and no statement about what to do if the id is unknown.

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