Universe relay with an exact homecoming

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

Annotations already declare openWorldHint=true, idempotentHint=true, destructiveHint=false and readOnlyHint=false. The description adds genuine context beyond that: it operates in a working directory (filesystem side effects), verifies homecoming exactly against the origin, refuses tampered packets, and consumes one job. It does not disclose what happens on failure, whether the working directory is created or must exist, or any permission requirements.

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 sentences, front-loaded with the tool's purpose and closed with inputs, returns, and cost. Sized reasonably, but the metaphorical narration ('born, hops between nodes, learns, and comes home') spends words on imagery rather than operational detail, so not every sentence earns its place.

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 the brief return-value summary is adequate and not a gap. Annotations cover the safety profile, so the description's added job is to explain inputs and side effects. It stops short: the working-directory contract, the meaning of 'key', and what the relay actually computes remain unstated for what appears to be a non-trivial, open-world, stateful operation.

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 0% and the schema exposes only an opaque 'params' object, so the description carries the full burden. It partially compensates by naming the expected inputs ('work_dir; optional key'), which the schema does not reveal, but it never explains the format of work_dir or what the optional 'key' is for (registration key? idempotency key?), and the named inputs do not visibly map onto the single params wrapper.

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 gives a verb and a resource ('Run a self-contained universe relay in a working directory') and sketches a flow (packet born, hops, learns, returns, verified), so the agent gets a rough idea. However the framing is heavily metaphorical ('universe', 'sealed packet', 'learns') and never states in plain terms what computation or simulation actually occurs, nor how it differs from siblings like singularis_dispatch or singularis_data_carry. Purpose is recognizable but vague.

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 use this tool versus the many sibling tools, no prerequisites, and no exclusions. The only orienting guidance is the cost note ('Cost: one job'), which tells the agent about budget but not about selection. The agent must infer applicability from the name alone.

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