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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so the safety profile is covered. The description adds real behavioral context beyond that: it enumerates the analysis output and discloses the returned breakdown_id token needed for the follow-up call. Auth requirements and rate limits remain unstated, keeping it out of 5 territory.

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 action, and the long opening clause is dense but every listed element is a distinct output. The input guidance and handoff token follow in two short sentences. Slightly run-on for a single sentence, but nothing is padding.

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?

There is no output schema, so the description carries the return-value burden and does so: it names the output fields and the breakdown_id handle. Combined with input options and downstream routing, an agent has everything needed to call it correctly.

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 100%, so the baseline is 3. The description adds the either/or semantics the schema does not express: supply a public link OR paste the text, framing them as alternative paths rather than values to combine. The optional 'notes' parameter is left to the schema.

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?

Specific verb+resource (reverse-engineer a competitor TikTok/IG Reels ad) with an enumerated scope of what gets extracted: hook type, segment structure, selling points, CTA. It also names the downstream sibling rewrite_ad_for_product, so the agent can place it in the workflow without opening other schemas.

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 tells the agent exactly which inputs to supply (public video link, or pasted ad text if already available) and what to do with the result by routing to rewrite_ad_for_product. It stops short of stating when NOT to use it or contrasting with siblings like generate_hooks or write_ugc_script.

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