Resolve a ticker

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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, so the safety profile is fully covered. The description adds useful context about the coverage universe (~4,700 US stocks/ETFs) and that it can match company names or partial tickers, but it does not substantially expand on behavioral details beyond what annotations and schema already indicate.

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 only two sentences, with the core purpose and an example stated first, followed by the usage directive. Every sentence earns its place, and there is no redundant or filler 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?

The tool is simple with only two parameters, rich annotations, and an output schema. The description covers the purpose, usage timing, and scope, so an agent has everything needed to select and invoke it correctly.

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 parameter semantics are already fully documented in the schema. The description adds a helpful example for 'query' but no additional meaning for 'limit' or deeper formatting details, so the baseline of 3 is appropriate.

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 clearly states a specific action ('Find the ticker'), the target resource (PairBook's ~4,700 covered US stocks and ETFs), and gives a concrete example ('nvidia' -> NVDA). It is clearly distinguished from siblings like compare_pair or weekly_returns because it is specifically a name-to-ticker resolver.

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 tells the agent when to use this tool: 'Call this before other tools whenever the exact ticker is uncertain or a lookup returned not-found.' This provides clear procedural guidance relative to all siblings, making the intended invocation order unambiguous.

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