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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so safety is covered; the description still adds real value by disclosing the returned payload (names plus domain, availability, price, and companion/TLD variants). No auth or rate-limit detail, but nothing contradicts the annotations.

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 sentence, front-loaded with the action and identifier, then the return contents. No padding or redundant restatement of the title.

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 must describe returns and does so reasonably well, though the internal shape of a 'name' entry (price currency, availability values) is only gestured at. For a one-parameter read tool, this is nearly complete.

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?

There is a single parameter with 100% schema description coverage (uuid-formatted run ID), so the schema carries the semantics. The description only says 'by id' and adds no format or sourcing guidance beyond the schema — the baseline 3 is correct.

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 precise verb and resource ('Get one brand-name run by id') and scopes it to a single run, which cleanly separates it from the plural sibling list_brand_names. The clause after the colon enumerates what comes back, so an agent knows the tool's shape without opening a 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?

Usage is implied by 'by id' — fetch the details of one already-existing run — but the description never states when to prefer this over list_brand_names or the per-domain checker, nor any prerequisite. Adequate but leaves routing to inference.

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