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

Annotations already cover the safety profile (readOnlyHint, non-destructive, openWorld), so the description's job is to add beyond that. It does: it discloses the return shape (top 3 candidates sorted by verified status and followers) and the recommended fallback loop for ambiguous names. It doesn't mention rate limits or auth, but for a read-only search this is solid added context.

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?

Three tight sentences, front-loaded with the usage trigger, followed by return behavior and a disambiguation strategy. No filler or restatement of the tool name.

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?

An output schema exists, yet the description still summarizes the shape of results (top 3, ordered), and it fully covers when to call it and what to do next. Nothing an agent needs to invoke it correctly 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 brand_names, context, and conversation_id are already documented in the schema. The description adds no syntax or format detail beyond the schema, so the baseline 3 applies.

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 ('find a brand's Meta Platform ID') and immediately clarifies the role versus get_meta_ads, which it names as the downstream step. An agent can distinguish this lookup tool from the ad-fetching siblings 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 frames the trigger ('Use this when you need to find a brand's Meta Platform ID') and provides a concrete disambiguation workflow: try each candidate with get_meta_ads and stop at the first that returns ads. This names both the condition and the alternative tool.

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