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

Annotations already cover safety (readOnly, idempotent, non-destructive, closed-world), so the description earns credit by adding data semantics: what a thread is not, the enumerated linkType vocabulary (deploys | trains_on | powered_by | fabricated_at), and that it is free on both tiers. It does not address result size or limits when `event_id` is omitted for the entire layer, which is a meaningful gap for an unbounded query.

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?

Purpose is front-loaded in the first clause, followed by disambiguation, usage modes, and the sibling pointer in a logical order. It is dense but nearly every sentence carries information; the 'Free on both tiers' note is minor but useful.

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?

With no output schema, the description appropriately describes what each link carries (sourced claim, linkType, asset, host-event field) and how to scope the query, which is enough to call it correctly. The only omission is any indication of pagination or volume behavior for the whole-layer call.

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. The description goes beyond the schema's brief note by explaining the directional meaning of the results for a given event_id and confirming that omitting it returns the whole layer, adding interpretive value the schema does not carry.

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 ('Retrieve Infrastructure Threads') and immediately defines the resource as the material-link layer where a named AI hardware asset appears as a documented fact in two events. It explicitly distinguishes this from 'Coordination Connection' ('no connection type, no confidence grade'), so an agent can separate it from get_connections without opening either 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 explicit routing: pass `event_id` for bidirectional linked events (outbound = assets this event deploys/trains on; inbound = events using this event's asset), omit it for the whole layer, and use `get_event_stack` instead for a single event's value-chain stack. Both the when and the alternative are named.

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