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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the agent knows it's a safe read operation. The description adds that the query can be a name, identifier, or plus country, and that it scans three countries, and returns a specific structure. However, it doesn't mention whether results are exhaustive or if there are limitations on query length or count. With annotations covering the safety profile, a 3 is appropriate as the description adds some behavioral context but not extensive.

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?

The description is a single paragraph of two sentences, which is reasonably concise and front-loaded with the alias note and alternatives. It packs essential information without excessive verbosity. However, it could be slightly more structured with a line break for readability, but overall it earns its place.

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?

Given that the tool has a single parameter, complete schema coverage, annotations for safety, and an output schema that defines the return structure, the description is almost complete. It explains the alias relationship, the query types, the geographic coverage, and the return format. The only minor missing pieces are details about pagination or limits, but these are not critical given the simplicity of the tool.

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%, so the schema already documents the 'query' parameter with examples and description. The description in the tool description largely reiterates the same information about the query being a name, identifier, or plus country, adding no new semantics beyond what the schema provides. Since the description does not add significant new meaning, 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?

The description states that the tool performs a search for companies across specific countries and returns a structured result with id, title, and url. It clearly identifies the resource and action. However, it doesn't explicitly distinguish its behavior from 'search_company' beyond noting it's an alias, which is a minor gap in differentiation.

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 description explicitly states that 'other clients should prefer `search_company`', which takes an explicit `country` and returns full SearchResult. This provides clear guidance on when to use this tool versus the sibling, and also indicates that this alias is intended for ChatGPT connectors. The description also outlines the acceptable query formats and the geographic scope, offering strong usage context.

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