Search Ticker by CIK / CUSIP / ISIN

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

Annotations already declare readOnlyHint=true and destructiveHint=false, establishing that this is a safe read operation. The description does not add extra behavioral details such as potential errors, case sensitivity, or return format. While it doesn't contradict annotations, it provides no additional transparency beyond the structured data.

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, compact sentence with no extraneous information. It directly states the purpose and essential identifier types, making it highly efficient and well-structured.

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 simple lookup tool with 2 required parameters and no output schema, the description is sufficiently complete. It covers what the tool does and the accepted identifier types, which is all that is needed for a straightforward lookup operation. The annotation provides safety context, so no further details are required.

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 schema already fully describes both parameters (type enum and identifier text). The description adds value by specifying the format lengths ('9-char' for CUSIP, '12-char' for ISIN) and clarifying that CIK is an SEC identifier. This extra context aids validation and helps the agent select the correct format.

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 the action ('Look up') and the resource ('stock ticker') and specifies the exact identifier types (CIK, CUSIP, ISIN), making it distinct from sibling tools like search_tickers which likely search by name/ticker. This is a specific verb+resource+scope definition.

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?

Usage is implicitly clear: use this tool when you have a CIK, CUSIP, or ISIN to find a ticker. However, there is no explicit guidance on when not to use it or mention of alternative tools like search_tickers for name-based searches. The context is implied rather than stated, so it stands at a baseline level.

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