Financial Modeling Prep MCP Server

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It mentions retrieving details but does not cover critical aspects like rate limits, authentication needs, error handling, or response format. The phrase 'Easily search' is vague and adds no substantive behavioral context, leaving significant gaps for an agent to understand operational traits.

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 concise and front-loaded, stating the core purpose in the first sentence and adding supplementary details in the second. It avoids redundancy and is appropriately sized for a simple search tool, though it could be slightly more structured by explicitly separating usage from output details.

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?

Given the lack of annotations and output schema, the description is incomplete. It mentions retrieving details but does not specify the return format or structure, leaving the agent uncertain about the output. For a tool with no structured behavioral data, more comprehensive context on response behavior and limitations is needed.

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 has 100% description coverage, with the 'isin' parameter fully documented. The description adds no additional semantic details beyond what the schema provides, such as format examples or validation rules. Since schema coverage is high, the baseline score of 3 is appropriate, as the description does not compensate but also does not detract.

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's purpose: 'search and retrieve the International Securities Identification Number (ISIN) for financial securities' and mentions retrieving key details like company name, stock symbol, and market capitalization. It specifies the verb ('search and retrieve') and resource ('ISIN'), but does not explicitly differentiate from sibling tools like 'searchCUSIP' or 'searchSymbol', which handle similar financial identifiers, leaving some ambiguity.

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 no guidance on when to use this tool versus alternatives, such as sibling tools like 'searchCUSIP' for CUSIP numbers or 'searchSymbol' for stock symbols. It mentions using the 'FMP ISIN API' but does not specify contexts, prerequisites, or exclusions, offering minimal usage direction.

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