Add asset to collection

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

Annotations already cover the safety profile (readOnlyHint=false, destructiveHint=true, idempotentHint=false). The description adds genuinely non-obvious behavior: unresolved request/vector references are materialized into assets before local collection state is mutated, and character collections are mutated indirectly via tag application. It still does not mention the confirm gate or the retry/idempotency story.

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?

Three short sentences, front-loaded with the core action and then the two non-obvious behaviors (materialization, character-tag path). No filler or restatement of the title.

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?

For an 8-parameter destructive write with a nested payload object, three body-input modes, and no output schema, the description omits the confirm contract ('set true only when the user asked for exactly this action') and the idempotency key, both of which materially affect correct invocation. It covers the asset-reference semantics well but leaves the safety-relevant inputs to the schema.

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 100%, so the baseline is 3, but the description adds real meaning: request_id and vector_id are alternative ways to name the asset and are materialized first. It does not explain the payload/payload_file/flat-body mutual exclusivity or the confirm parameter, which remain schema-only.

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 (add an asset to a collection) and distinguishes the two collection types it applies to (manual vs character). The inverse sibling remove_asset_from_collection is never named, but the operation is unambiguous and the character-collection nuance goes beyond a bare restatement.

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?

The description implies when to use it (adding an asset to a manual or character collection) and gives a conditional rule for character collections, but never states when NOT to use it, nor points to alternatives such as remove_asset_from_collection or create_asset_character. Usage is inferable rather than explicit.

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