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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so the description's "Read-only" largely restates structured data. It does add genuinely new context — "free" (no cost) and the stable-vs-live distinction, which is a behavioral trait about data freshness not covered by any annotation. That earns partial credit but not a high score on its own.

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 sentences, front-loaded with the payload contents and closed with the stable-vs-live qualifier. It is dense but every clause describes an actual field of the snapshot, so nothing is wasted; the long comma list is slightly harder to scan than a bulleted form but acceptable.

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?

With no output schema and no parameters, the description carries the burden of telling the agent what it gets back, and it does so thoroughly by enumerating the snapshot's contents. Combined with the free/stable qualifiers, an agent has enough to decide and call correctly; only the explicit relationship to live-signal siblings 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?

The tool takes zero parameters, so there is no parameter semantics for the description to clarify; the baseline for a parameterless tool is 4. Nothing here misleads about inputs.

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 concretely enumerates what the snapshot contains (positioning, discoverability score, prioritised actions, competitor set, day-0 SEO/AI baselines), which is far more specific than the title. It also implicitly distinguishes itself from live-signal siblings like get_seo or get_visibility by framing this as stable baseline context. It stops short of a clean verb+resource statement and never names a sibling, so it lands just under a 5.

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 stable business context, not live signal data" gives an implied selection rule against live-data tools, which is useful. However, it never names the alternatives (get_seo, get_visibility, get_business_context) or states explicitly when an agent should fetch this rather than those. Usage is inferable but not spelled out.

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