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

Annotations already cover the safety profile (readOnlyHint, openWorldHint), and the description adds useful behavioral context the annotations don't carry: the auth requirement and the semantic distinction between 'pdf_long' (one continuous strip) and 'pdf_a4'/'pdf_letter' (sliced to page). It does not discuss the download link's lifetime or any rate limits, keeping it short of 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?

Front-loaded with the core action, then format semantics, then scope/auth. Every clause carries information with no filler, though the parenthetical format explanation slightly interrupts the flow.

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?

Since an output schema exists, return values need not be explained; the description covers purpose, auth, scope and format semantics. Missing only minor operational detail (link lifetime, whether repeated calls regenerate links).

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 67%, and the only enum without a schema description (format) is explained in the description via the pdf_long vs pdf_a4/pdf_letter distinction. It adds real meaning over the schema for the highest-choice parameter, though it leaves box, grid, show_title and strip_shape to their schema descriptions.

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 a specific verb and resource ('Creates a download link for one box version of a song') and enumerates the concrete outputs (MIDI file, printable strip PDF). An agent can immediately tell this is the export/generation path, distinct from siblings like import_midi or get_song.

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?

'Works on the person's songs and on public tunes' clarifies the scope of what can be exported, and 'Requires signing in' sets an access precondition. It stops short of naming when to prefer an alternative, but for an export tool with no true sibling alternative this is adequate context.

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