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

Annotations already declare readOnly, idempotent, non-destructive, closed-world behavior, so the description does not need to restate safety. It instead adds genuinely new behavioral context: unsourced fields return null and are listed as withheld, missing names produce an error rather than a clean result, and the score is explicitly framed as an opinion. No auth, rate-limit, or pagination details, but none appear applicable to a single-record read.

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 tight sentences that lead with the capability and follow with return contents, usage scope, and the error caveat. Dense but every sentence adds information the agent needs; no filler or 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?

An output schema exists, so return shapes need not be spelled out, yet the description still summarizes them and additionally covers null handling and error semantics. For a one-parameter read tool with full annotations, nothing an agent needs to call it correctly is missing.

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 0% and the single parameter has no description, so the description carries the burden. It clarifies that 'name' accepts a brand, store, or company name and implies a single known value rather than a search query. It does not specify matching behavior (exact vs. fuzzy) or format expectations.

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 ('look up one brand, store or company by name') and enumerates exactly what comes back: parent company, ownership type, source links, and a Shoptegrity composite score. An agent can distinguish this from search_top_brands or lookup_brand_integrity 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?

'Use it for a single known name' gives an explicit usage condition that separates it from browsing/searching siblings. It also warns that a missing name returns an error that is not a negative finding, which prevents a common misinterpretation. It stops short of naming the alternative tool to use when the name is unknown or when integrity details are needed.

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