Check Saved Audiobooks

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

Annotations already declare readOnlyHint, idempotentHint and openWorldHint, so the safety profile is covered. The description adds real behavioral context beyond that: upstream batching in chunks of 40 and a 50-ID request cap, which tells the agent to expect batched network behavior. It stops short of saying what happens when more than 50 IDs are supplied (error, truncation, or split).

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?

One front-loaded sentence carries the action and the batching detail, followed by compact Args/Returns lines. No filler, and the key constraint appears before supporting detail.

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?

An output schema exists, so the description need not detail the response, yet it still clarifies that results map each audiobook ID to a boolean. Combined with annotations and the input format/limit disclosure, this is nearly complete; the only gap is the unspecified behavior when the cap is exceeded.

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 description coverage is 0%, so the description must carry the load, and it does: the single argument accepts 'Audiobook IDs or URIs' (the URI form is not evident from the bare string-array schema) and is bounded at up to 50 entries. That is meaningful added semantics for the only parameter.

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+resource pair ('Check which audiobooks are already saved'), which clearly reads as a membership/batch lookup rather than a full listing. It is distinguishable from siblings like get_saved_audiobooks, save_audiobooks and remove_saved_audiobooks by implication, but the description never names an alternative explicitly.

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 implied by the name and the 'check' wording: use it to test membership before saving/removing. There is no explicit when-to-use vs get_saved_audiobooks (which would list everything) or vs check_saved_tracks/check_saved_shows, so the agent must infer the routing.

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