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

Annotations declare it is non-readonly and non-destructive but say nothing about cost, latency, or data preservation; the description fills all three gaps — one LLM call plus page fetches, 20-60 second blocking behavior, and that user-added entries are carried forward. That is exactly the context an agent needs before invoking an expensive blocking operation.

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 sentences, zero padding: what it does, what it preserves and how long it takes, and when to prefer it over the sibling. The cost/latency warning is front-loaded in the first sentence rather than buried.

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 non-readonly, non-idempotent, blocking regeneration tool with no output schema, the description covers inputs, runtime cost, and preservation semantics completely. It stops short of saying what the call returns or how to inspect the result, though get_research_brief is available as a companion.

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% for both parameters, so the schema already documents site and keepScalars. The description's explanation of keepScalars ('keeps the current businessSummary, audience and geography text') is nearly a restatement of the schema text, so it adds little beyond the baseline.

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 (Rebuilds) plus resource (the research brief) and enumerates the exact inputs it draws from: live site, products, Search Console queries, and manual keywords. This clearly separates it from the sibling update_research_brief, which the description explicitly names as the alternative.

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?

Gives an explicit when-to-use condition ('when the business changed or the brief looks off') and an explicit when-not with the alternative tool ('otherwise edit single fields with update_research_brief'). The routing decision is fully determined without opening any schema.

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