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

No annotations are provided, so the description carries the full burden. It explicitly states 'WRITE TOOL' and discloses the major side effect: 'saving resets the card's status to pending, so the ad STOPS running until a person approves it again.' It also mentions character caps and style constraints. This is excellent transparency for a mutating tool.

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?

The description is moderately long but every sentence earns its place. It front-loads the core purpose and partial-update behavior, then the cost warning and user-agreement requirement, then caps and style. The structure is logical and scannable, though it could be tightened slightly 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 write tool with no annotations and no output schema, the description covers all essential contexts: what it edits, how to use it (partial updates), the side effect and user consent requirement, field caps, and style guidance. An agent has everything needed to invoke it correctly and safely. Nothing critical is missing.

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 each parameter is already documented. The description adds extra semantic nuance: 'url must be https', 'domain must be a bare hostname like myapp.com', and house style rules ('plain words, no exclamation marks', 'says what the product does'). These go beyond the schema's basic descriptions, adding real value for the agent on how to formulate parameter values.

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?

The description opens with 'Edit this advertiser's ad card', a specific verb and resource. It clearly distinguishes from the sibling tools, which are all read-only getters (get_my_stats, get_network_pulse, get_slot, list_free_slots). No ambiguity about what the tool does.

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?

Provides explicit usage guidance: 'Pass only the fields to change; anything omitted keeps its current value' tells the agent how to perform partial updates. It also instructs the agent to get user agreement before calling ('Say that to the user and get their agreement before calling this'). While it doesn't name alternatives, the siblings are all reads, so no alternative is needed.

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