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

Annotations already cover the safety profile (readOnly, non-destructive, closed-world), and the description adds a real behavioral contract beyond them: the `{ ok: false, error }` failure shape and an instruction not to retry blindly. It does not describe the success payload, but no output schema exists so that gap is modest.

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 core capability is front-loaded in the first sentence and the error-handling note follows as a secondary paragraph. The error sentence is somewhat verbose for what it conveys, but every part carries actionable 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 read-only lookup with annotations and no output schema, the description covers purpose, failure semantics, and error recovery well. However, with two of four parameters lacking schema documentation and no stated relationship between ID and domain lookup, an agent could not confidently determine which key to supply.

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 50% — context and llm_model are documented, while domain and advertiserProjectId have no schema descriptions. The description partially compensates by clarifying that domain accepts a URL form and that ID is an alternative key, but it says nothing about precedence, mutual exclusivity, or fallback behavior, so the undocumented parameters remain underspecified.

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 and resource ('Get advertiser project details') plus the two lookup keys (project ID or domain/URL) and the organizational scope. It is clearly distinct from get-projects in intent, though the description never names that sibling explicitly.

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 two accepted lookup modes imply when the tool applies, but there is no explicit guidance on choosing this over get-projects, nor whether one of advertiserProjectId/domain is required or what happens if both are supplied. Usage is inferred rather than stated.

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