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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, so the description only needs to add context beyond those. It adds the external API source, states that no API key is required, and mentions that an optional key raises rate limits. This is useful behavioral context, though it does not go into failure modes or rate-limit edge cases.

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 compact, front-loaded with the core action, and uses bullet points for usage scenarios. Every sentence serves a purpose, and there is no filler or repetition of schema content.

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 a rich schema and an output schema, the description covers the necessary context: what it searches, what it returns, when to use it, which sibling to prefer instead, and external API constraints. No critical information for selecting or invoking the tool 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?

The description only paraphrases the main search concept ('by name or keyword') and references instrument categories like ETFs, options, and futures. The nested input schema already documents query, exchange_code, security_type, limit, and other filters with examples, so the description does not need to repeat them. It adds some high-level context but does not substantially extend the schema's 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 opens with a specific verb and resource: 'Search Bloomberg OpenFIGI for financial instruments by name or keyword.' It also lists the returned fields (FIGI, ticker, exchange, security type, composite FIGI) and names the sibling tool MapInstrumentIds, making the tool's identity and scope immediately clear.

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 includes an explicit 'Use this tool when' bullet list covering common lookup scenarios and provides a clear exclusion: 'Use MapInstrumentIds instead if you already have a specific ID to convert.' This tells the agent exactly when to choose this tool versus an alternative.

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