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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, open-world), so the description earns credit for adding context they cannot: an explicit $0.50/call cost and the MPP/Stripe payment handshake, including the -32042 error and the credential retry path. It does not disclose latency, rate limits, or snapshot freshness/coverage windows, keeping it short of a 5.

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 cost so an agent sees the billing implication before anything else, and no filler. The payment sentence is dense but every clause (protocol, error code, retry field) carries necessary information.

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, so return values need not be explained, and annotations plus the payment note cover safety and billing. What is missing for a tool in a cluster of nine overlapping intelligence siblings is any routing logic explaining when this snapshot is the right call versus global_brief, deep_research, or free_preview.

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?

With zero declared parameters the baseline is 4, but the description instructs the caller to retry with params._meta["org.paymentauth/credential"] while the schema declares an empty properties object and additionalProperties:false. That reference is useful operational detail yet sits in tension with the schema, so the param story is only partially coherent.

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 names a concrete artifact ('global intelligence snapshot') and enumerates its coverage domains — official filings, procurement, infrastructure, markets, evidence-ranked relationships — so an agent knows what it returns. It does not, however, distinguish itself from near-siblings like shadowgraph_global_brief or shadowgraph_deep_research; 'fast' only implicitly contrasts with deep research.

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?

There is no statement of when to choose this tool over the nine siblings, no exclusions, and no mention of alternatives such as shadowgraph_free_preview or shadowgraph_global_brief. The only procedural guidance is the payment retry flow, which is operational rather than a selection criterion.

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