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

Beyond the annotations (readOnlyHint, openWorldHint, destructiveHint), the description explains concrete behaviors: the gateway NEVER writes, write attempts are refused with a directive to use call_write_tool, arguments are validated server-side and produce precise errors, and credits/access rules match direct invocation. This meaningfully extends the annotation-only profile without contradiction.

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?

The description is dense but purposeful, front-loading the core purpose and read-only guarantee before the usage workflow. Every sentence contributes useful information, such as the discovery prerequisite, validation behavior, and write-refusal routing. No filler or redundancy.

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 gateway tool with dynamic targets, the description is complete: it explains how to discover target tools, what data domains are reachable, how writes are blocked, how errors are surfaced, and how credits behave. The presence of an output schema means return-value details are not required here.

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 0%, so the description carries the full burden for parameter meaning. It explicitly defines both parameters: 'name = exact tool name' and 'arguments = that tool's parameters as an object.' It also explains that arguments are validated against the target tool's schema, compensating well for the absence of schema descriptions.

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 clearly states the tool's purpose: 'Run a READ-ONLY Opus tool by name — the gateway to every reporting/listing capability that is not in your visible core set.' It specifies a verb, a resource, and a scope, and distinguishes itself from the sibling call_write_tool by emphasizing read-only behavior.

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 gives explicit guidance: use search_tools(query) FIRST to discover the exact tool name and schema, then call this gateway. It also states when not to use it — if the named tool modifies data, it is refused and call_write_tool should be used instead. This clearly routes the agent between alternatives.

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