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

Annotations already declare it read-only, idempotent, closed-world and non-destructive, so the bar is lower; the description still adds real value by disclosing the response contents, the 'never invents lookalikes' accuracy guarantee, and a cost of 1 credit. It does not state what happens when zero collisions exist, which keeps it from a 5.

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 dense sentences with the return payload front-loaded and no filler. The telegraphic fragments ('Cost 1.') are efficient but slightly terse for an unfamiliar domain concept like 'official_for'.

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?

No output schema exists, and the description compensates by naming the fields returned. Combined with the cost and anti-hallucination guarantee, an agent has enough to call it correctly, though the empty-result behavior remains unspecified.

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% with a single well-documented parameter, so baseline is 3. The description goes beyond it by clarifying that the match is exact and by explaining the matching rule — same namespace brand or tail — which is not in 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?

States a specific resource and scope — 'one exact server_name' — and enumerates the return fields (official_for, name_collision_count, up to 10 other names). The word 'exact' implicitly separates it from fuzzy siblings like census_search or census_lookup, though no sibling is named outright.

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 explicit when-to-use, when-not-to-use, or named alternative among the 14 siblings; an agent must infer that this is the identity-disambiguation step versus census_lookup or census_search. 'Cost 1' hints at a credit budget but gives no routing rule.

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