Add asset to collection

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

Annotations already declare destructiveHint=true, idempotentHint=false, and openWorldHint=true, so the safety profile is covered. The description adds genuine behavioral context beyond that: unresolved references are materialized before local collection state changes, and character collections are mutated by applying a character tag. It omits the confirm-gating requirement, which is left to the schema.

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 tight sentences with the core action front-loaded and the collection-type nuance following. No filler, though the materialization sentence and the character-tag sentence could be compressed into one.

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 a destructive, non-idempotent mutation with 8 parameters and a nested union body, the description covers the collection-type behavior and reference materialization, and the schema plus annotations carry the rest. It does not mention the confirm requirement or retry/idempotency-key semantics, but with full schema coverage and no output schema those gaps are minor.

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 schema already documents all 8 parameters, including the mutually exclusive payload/payload_file/flat-flag body inputs. The description only echoes request_id/vector_id and explains their materialization effect, adding little syntax or format detail beyond the structured fields. Baseline 3 is appropriate.

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 (add) and resource (asset to collection) and goes further by distinguishing two target types: manual versus character collections, noting the character-tag mechanism used for the latter. An agent can tell this apart from the sibling remove_asset_from_collection 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?

The description tells the caller to supply a request ID or vector ID, which is closer to parameter guidance than to when-to-use guidance. It never names the alternative (remove_asset_from_collection) or states any exclusion, so usage context is implied rather than explicit.

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