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

Annotations (destructiveHint=true, idempotentHint=false, openWorldHint=true) are consistent with the described atomic replace. The description adds substantial extra context beyond annotations: the atomic link+unlink behavior, the dry-run semantics of confirm=false vs confirm=true with read-back, the fact that auto-created logos are untouched and do not block the swap, and the 1:1 ≥128x128 asset constraint.

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 action and the failure mode of alternatives, and consistently dense with operational detail. It runs to three paragraphs, so it is longer than strictly needed, but nearly every clause carries decision-relevant 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?

Given a 4-param mutation tool with an output schema (so returns need not be explained) and destructive annotations, the description covers prerequisites, dry-run safety, side effects, and per-campaign scope. An agent can call it correctly and safely without further context.

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 0%, so the description carries the full burden and does: asset_id is documented as both the target asset (already in library, square, ≥128px) and as a read-mode switch when empty; confirm is documented as dry-run vs apply with result read-back. Only customer_id is left implicit, which is self-evident.

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 precise verb+resource+scope: it replaces the BUSINESS_LOGO shown in a campaign's ads, atomically swapping the old advertiser logo for a new one. It explicitly distinguishes itself from manage_extension_assets (which fails on the one-logo limit) and upload_image_asset (which must run first).

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 the triggering scenario (rebrand, old logo still on ads), explains why the naive alternatives fail, names the prerequisite upload step, and states the per-campaign repeat requirement. It also defines the read-only mode via empty asset_id, so the agent knows when not to mutate.

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