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

With no annotations present, the description carries the full burden of behavioral disclosure. It only states that the tool provides access to CIK numbers, but does not explain what the response contains, whether results are paginated, how the 'limit' parameter affects behavior, or any other operational detail. This is a significant gap for a data retrieval tool.

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 sentences. The first sentence is informative, but the second sentence is promotional and adds no technical value. It is reasonably sized but includes unnecessary marketing language, preventing a high score.

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 tool with one optional parameter and no output schema, the description should clarify what the endpoint returns and how the limit applies. It only gives a general overview of the data source, leaving the agent without essential information about the response structure or usage constraints. This is incomplete even for a simple tool.

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 input schema describes the 'limit' parameter with its default value, achieving 100% coverage. The description adds no parameter-specific information, but the schema already handles it, so a baseline of 3 is appropriate. The description does not enrich the meaning beyond the schema.

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 tool accesses a database of CIK numbers for SEC-registered entities, with the resource named as the FMP CIK List API. It uses a specific verb ('Access') and resource, but does not explicitly distinguish itself from sibling tools like searchCIK or getCompanyProfileByCIK.

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 provides use case context (regulatory compliance, financial transactions, investment research) and identifies target users, but does not mention when NOT to use it or point to alternatives. This is clear context without exclusions, matching a score of 4.

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