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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description goes beyond them by disclosing the shape of each returned record (domain, name, category, signature color), which matters because there is no output schema. It still says nothing about result caps or pagination.

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 that leads with the primary lookup keys and appends the optional filter, with no filler or repetition of the annotations.

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 two-parameter, zero-required search with no output schema, the definition covers purpose, search keys, optional filter, and the returned fields. The one real gap is the missing routing versus get_brand, which an agent must guess at.

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 schema already documents both parameters including the substring semantics and the empty-string behavior. The description's 'by name or domain' and 'optionally within a category' merely restate that, adding no new syntax or format detail. Baseline 3 is correct when the schema does the heavy lifting.

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 ('Find brands in the WikiBrand catalogue') plus the searchable keys (name or domain) and an optional scope (category). It is clear on its own, but never names or distinguishes itself from the sibling get_brand, leaving the single-vs-multi lookup boundary to inference.

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 only implied: 'optionally within a category' and the schema note 'Empty lists everything' tell the agent the tool works as a broad or narrow list. There is no explicit guidance on when to prefer get_brand for an exact brand rather than searching, and no stated prerequisites or limits.

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