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

Annotations only declare the safety profile (readOnlyHint=false, openWorldHint=true, non-idempotent, non-destructive); the description adds genuinely new context: it behaves exactly like a direct call, read tools require no auth, money/account tools require a signed request with the account key and may spend from the balance, and failures return the tool's refusal with the reason. These auth and cost traits are not derivable from the annotations.

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 core action; the discovery-tool routing, auth requirement, and return behavior follow compactly with no filler or repetition.

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 generic proxy with no output schema, the description covers purpose, the discovery workflow that produces targets, auth/payment behavior, and return semantics (result or refusal reason). Nothing needed to invoke it correctly is missing, apart from the minor arguments-format detail.

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% and both parameters (name, nested arguments) are undocumented in the schema, so the description does the work by conveying that 'name' is the target tool and 'arguments' are that tool's arguments. However, it never specifies that 'arguments' must be a JSON object matching the target tool's input schema, leaving format ambiguity.

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+resource ('Call any of the hub's tools by name with its arguments') and explicitly differentiates from siblings by naming search_tools and describe_tools as the discovery chain that feeds it. An agent immediately knows this is the generic invocation proxy, not a search or describe tool.

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 — reaching tools 'this door does not list' — and names the two sibling tools that identify those targets. Also states the invocation prerequisite (read tools need nothing, signed requests needed for money/account-acting tools), so the agent knows both the trigger and the setup.

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