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

Annotations already establish readOnlyHint=true and openWorldHint=false, so there is no contradiction. The description adds value by disclosing the retrieval scope: all names with per-name domain, availability, price, and companion/TLD domains — useful context not inferable from annotations or schema alone.

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?

A single, front-loaded sentence states the action and then the key output details after a colon. Every element earns its place and there is no filler.

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 low-complexity read-only tool with one required parameter and no output schema, the description explains the expected return content well enough to invoke correctly. It does not detail exact field formats or error behavior, but the absence of an output schema makes the provided output summary reasonably sufficient.

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% for the single id parameter, including format and description ('The brand-name run ID'). The tool description repeats 'by id' but adds no parameter semantics beyond the schema, so it sits at the baseline.

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 uses a specific verb and resource — 'Get one brand-name run by id' — and enumerates what is included: names, domain, availability, price, and companion/TLD domain variants. This clearly distinguishes it from list_brand_names, create_brand_names, and delete_brand_names.

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 'by id' phrasing establishes the clear context: use this when you already have a run id and need one run's full name details. It does not explicitly cite alternatives like list_brand_names, but the usage context is unambiguous and no exclusions are needed.

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