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

Annotations already declare readOnly/openWorld/non-destructive, and the description adds substantial context on top: typical 5-8s latency, x402 per-call payment, no charge on timeout failure, and the rule that facts appear only when sources state them with conflicts resolved to the most recent dated figure.

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-loads what is returned and the response shape, then layers timing, input guidance, sourcing rules, and payment terms. Every sentence carries information, though the run is dense enough that a reader must parse several distinct concerns in one block.

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 structure needn't be explained, yet the description still covers cost model, failure behavior, latency, and sourcing caveats. Nothing an agent needs to decide to call it, or to interpret a failure, 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 coverage is 100%, so the baseline is 3, but the description meaningfully enriches the single parameter: a website address avoids name clashes while a bare name resolves to the best-known match, and ambiguity is surfaced in the output. That is real semantics beyond the schema's 'company name or website' text.

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 ('Returns a short sourced brief on one company') and enumerates the returned fields, so an agent can distinguish it from research.answer, research.market, or page.summarize 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?

Gives clear usage context: pass a website to avoid name clashes, bare names resolve to the best-known company, and ambiguity is flagged in the summary. It does not explicitly name a sibling tool or state when a different research tool would be preferable, so it stops short of full routing guidance.

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