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

With no annotations provided, the description carries the full burden of disclosing behavioral traits. It merely states it 'Accesses historical employee count data' without mentioning whether it is read-only, any rate limits, pagination behavior, or what the response structure contains. The 'specific reporting periods' are vaguely referenced but not clarified.

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 and mostly focused. The first sentence defines the tool's purpose, while the second adds context about growth trends and operational changes. The mention of 'FMP Company Historical Employee Count API' is somewhat redundant but not excessive. It is concise overall.

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 data-retrieval tool with two well-documented parameters, the description provides adequate but not rich context. It fails to explain what 'reporting periods' means or what the response contains, and it does not distinguish from the sibling getEmployeeCount tool. Given the lack of output schema, more detail about return values would improve completeness.

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 fully describes both parameters (symbol and limit) with clear descriptions, so schema coverage is 100%. The description adds no additional parameter detail beyond what the schema provides, warranting the baseline score of 3.

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 historical employee count data for a company using 'specific reporting periods', which is a specific verb+resource combination. However, it does not explicitly differentiate from the sibling tool 'getEmployeeCount' (likely current data), so it misses the opportunity to distinguish between historical and current employee count tools.

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?

No guidance is provided on when to use this tool versus alternatives. The phrase 'allowing users to analyze growth trends' implies some use cases, but there is no explicit 'use this for historical, use getEmployeeCount for current' or any exclusionary criteria.

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