add manga to list

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

Adds substantial behavior beyond the destructiveHint=true annotation: never overwrites existing entries, preview/confirmation_id/confirmed flow, and dry_run previewing. The claim that ordinary single-entry changes execute directly is slightly in tension with a blanket destructive hint, and there is mild redundancy with the schema's confirmed/confirmation_id descriptions, keeping 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?

Front-loaded with the core constraint (add only, no overwrite), then the safety flow. Dense but each sentence carries operational meaning; the confirmation sentences are somewhat long and restate schema parameter descriptions.

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?

No output schema, 8 parameters, and a mutation of a user's list — the description covers the safety-critical pieces (preview, confirmation, dry_run, non-overwrite, required status). It stops short of describing what a preview result looks like or what the title-resolution failure path returns beyond the schema note.

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?

With 63% schema coverage, the description compensates by stating that status is mandatory, that score follows the account's format, and that omitted fields are preserved (an important semantic not in the schema). confirmed/confirmation_id/dry_run guidance duplicates schema text rather than adding to it.

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?

"Add verified manga only if no entry exists" names a specific verb and resource, and the 'no entry exists' clause plus 'Existing entries are never overwritten by add' clearly delineates it from add_anime_to_list and update_list_entry. An agent can pick this tool without opening the schema.

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?

Gives clear when-to-use conditions (verified manga, no existing entry, status required) and an explicit branch for destructive/bulk changes with a confirm-then-retry procedure. It does not explicitly name update_list_entry as the alternative for existing entries, so routing is implied rather than stated.

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