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

Annotations already declare readOnlyHint/openWorldHint/non-destructive, so the safety profile is covered. The description still adds real context: it describes the returned shape (each batch with release, size, redeemed count; codes with redemption status) and states the auth requirement ('Cotlet API key with access to this app').

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?

The with-batch_id behavior is stated twice in near-identical wording ('the codes of one batch' and 'returns every code of that batch'), which is redundant. The front-loaded distinction is good, but the sentence is clunky and could be tightened considerably.

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 returns, and it does — enumerating the fields the agent will get back in each mode. Auth is noted, so an agent has enough to call it correctly; only the sibling-relationship detail is missing.

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 batch_id is already documented, giving a baseline of 3. The description goes further by contrasting the two behaviors of the parameter (summary of all batches vs. full codes of one batch), adding meaning beyond the terse schema description.

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 tool is clearly a list operation on Bandcamp track/album codes, and the two operating modes (with vs. without batch_id) are stated. However the opening phrase 'Your code batches with how many are redeemed' is grammatically garbled, and it never names the obvious sibling bandcamp_generate_track_album_codes to distinguish listing from generating.

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 explains the internal behavior switch — no batch_id returns a batch summary, batch_id returns one batch's codes — which is useful implied usage. But it offers no guidance on when to reach for this tool rather than the sibling generate_track_album_codes, and no prerequisites beyond the auth note.

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