ads_yandex_direct_write

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

With no annotations, the description carries full burden and does well: it discloses the confirm requirement, idempotency semantics, and that creation/deletion are out of scope. It stops short of describing what happens on partial batch failure, error responses, or permission/auth requirements for the mutation.

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?

Two tight sentences with the core action front-loaded, followed by scope boundaries; no filler.

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?

Covers the safety and scope story well, but for a batch mutation tool accepting up to 100 items with no output schema and no annotations, it should say more about batch-level behavior (atomicity, partial failure) and what a successful call returns.

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 only 20%, but the description indirectly contextualizes several params: 'explicitly confirmed' (confirm), 'idempotent' (idempotency_key), 'lifecycle status changes' (method enum), and 'campaign change' (service const). It adds no detail on the items array shape or the 100-item batch limit, so it only partially compensates for the sparse schema.

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 (apply change), resource (Yandex Direct campaign), and scope (existing campaigns only), and explicitly contrasts with the sibling create tool while declaring deletion disabled. An agent can distinguish it from ads_yandex_direct_create_campaign 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?

Explicitly says when to use it (updates and lifecycle status changes for existing campaigns), names the alternative for creation, and states the exclusion (deletion disabled). Nothing about routing is left to inference.

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