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

Annotations already carry readOnlyHint=true and destructiveHint=false, and the description does not contradict them. The description adds real behavioral value beyond the annotations by mandating that results be disclosed as Sponsored Brand Content, which is a presentation/compliance requirement the structured fields do not capture.

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 short sentences with minimal waste, and the core purpose is front-loaded in the first sentence. The disclosure requirement earns its place as a needed behavioral note, though it could have been integrated more cleanly rather than as an all-caps standalone sentence.

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, non-destructive retrieval tool with a full output schema and 100% parameter coverage, the description is largely complete: it states what it does and the one required behavioral constraint (disclosure). The only real gap is the missing when-to-use guidance relative to sponsored_search, but given the low complexity this is not a critical omission.

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 every parameter (brand_query, tenant_id, context) is already documented with clear descriptions. The tool description adds no additional parameter meaning, placing it at the baseline of 3, which is appropriate when the schema does the heavy lifting.

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 uses a specific verb (get) and resource (sponsored brand content and storytelling), making the purpose clear. However, it does not explicitly differentiate from the sibling sponsored_search, which could plausibly also return sponsored content, so it does not fully distinguish itself.

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 description contains no guidance on when to use this tool versus its siblings. Given the sibling sponsored_search covers a semantically adjacent area, routing guidance would be valuable, but none is provided. The REQUIRED disclosure line is a compliance directive rather than when-to-use versus alternative guidance.

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