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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, covering the safety profile. The description adds that it returns a list with sector and market cap and emphasizes it is not an answer-producing tool. It does not mention pagination or limit behavior, but given the annotation coverage, the added routing context justifies a 4.

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 two concise sentences plus a clear ROUTING directive. It front-loads the purpose and then gives actionable routing. No wasted words; every sentence 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 the tool has only 3 optional parameters, an output schema, and annotations covering read-only/idempotent behavior, the description fully covers what an agent needs: how to use it, what it returns, and how to proceed after searching. The routing guidance is especially valuable given the large sibling set.

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% — every parameter (limit, search, sector) has a description. The tool description does not add extra parameter-level meaning; it only restates search by name or ticker, which is already in the schema. Baseline of 3 is appropriate since schema handles parameter documentation.

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 a specific verb ('Search') and resource ('NZX-listed companies') with clear scope (by name or ticker) and output (list with sector, market cap). It distinguishes itself from the many get_* siblings by framing itself as the lookup step.

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?

Explicitly instructs when to use: 'Use this to find a company ticker before calling other tools.' Provides routing: 'a lookup step, not an answer' and names specific alternatives (get_credit_ratings, get_executive_compensation) plus the warning 'Do not stop after searching.' No ambiguity about how it fits among siblings.

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