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

Annotations already declare idempotentHint=true, destructiveHint=false and readOnlyHint=false, so the safety profile is covered. The description adds the partial-update semantics ('and/or', omit to keep) and the workflow link to choose_card, but never mentions the dry_run preview path that the schema exposes.

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 sentence, no filler, and the operation plus its required provenance (card_id from choose_card) is front-loaded. Nothing could be cut without losing information.

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 small 4-param mutation with annotations covering reversibility and idempotency and no output schema, the description supplies the needed workflow context. Only the dry_run preview behavior is left entirely 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 coverage is 75%, and the one gap is the required card_id, which the description explicitly explains as coming from choose_card's return value. color and message are already covered by schema descriptions, so the description usefully compensates for the undocumented 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 (changes) and the exact mutable fields (inside message and/or color) on a named resource (card). It also ties the tool to its sibling choose_card, so an agent can distinguish it from create_share/order_card without opening a 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 a clear prerequisite chain: the card is chosen with choose_card, and this tool takes the card_id that choose_card returned. It does not state when-not to use it (e.g. 'use order_card to create a new card'), but the sequencing guidance is explicit.

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