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

Annotations already declare read-only, idempotent, and non-destructive behavior. The description adds context beyond those annotations: it identifies the external source, states that no API key is required, and notes the optional-key rate-limit effect. There is no contradiction with 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?

The description is front-loaded with the core statement, uses scannable bullets for usage guidance, and closes with a concise source/auth note. Every sentence adds distinct value and nothing feels redundant.

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 search tool with an output schema and safety annotations, the description covers selection cues, result contents, the relevant sibling, and auth considerations, so return values need no restatement. It does not discuss optional filters or empty-result behavior, but the schema and annotations cover much of that residual need.

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?

Given the 0% schema description coverage, the description should compensate, but it only contextualizes the search query concept ('by name or keyword') and says nothing about the wrapper `params` object or meaningful options such as `limit`, `exchange_code`, `security_type`, or `source_resource_id`. The nested schema definitions contain details, but the tool description itself adds minimal parameter guidance.

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 clear verb ('Search'), resource ('Bloomberg OpenFIGI'), subject ('financial instruments'), and explicit scope ('by name or keyword'), then lists returned identifiers. It also names MapInstrumentIds as the sibling to distinguish from, so an agent can tell them apart.

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?

Provides an explicit 'Use this tool when' list with concrete conditions, and an explicit when-not with the alternative: 'Use MapInstrumentIds instead if you already have a specific ID to convert.' This is direct routing guidance.

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