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

With no annotations, the description carries the behavioral burden and does add a meaningful side effect: successful calls consume Nexus credits. However, it does not disclose error behavior, return format, authentication requirements, or what happens on invalid tool_ids, which are relevant for a tool that forwards arbitrary input.

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?

Three short sentences, each earning its place: purpose, prerequisite workflow, and consequence. The most important operational guidance is front-loaded before the credit-cost caveat.

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?

The description covers the core invocation flow and the credit side effect, which is enough for basic use. However, with no output schema and no annotations, it should also clarify what the tool returns and how failures are surfaced; those gaps matter for an arbitrary-tool gateway.

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 description coverage is 100%, so the schema already documents tool_id, input, and options. The description only reinforces that tool_id comes from nexus_search and that input is forwarded, adding no material semantic value beyond the schema.

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 states a specific action—'Route a tool call through HumanMirror Nexus'—and immediately gives the operational sequence: use nexus_search first, then invoke the selected tool_id. This clearly separates nexus_call from nexus_search by making the search step a prerequisite.

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 explicitly tells the agent when to use this tool: after nexus_search has returned a tool_id. It does not enumerate exclusions or alternatives among the other sibling tools, but the sequencing guidance is clear and practical.

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