plaid-mcp

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

With no annotations provided, the description carries the full burden. It discloses key behavioral traits: 'Live balance lookup' implies read-only operation, 'hits Plaid' indicates external API calls, and 'not cached' clarifies data freshness. However, it doesn't cover error handling, rate limits, authentication needs, or response format details.

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 extremely concise and front-loaded: two brief sentences with zero wasted words. Every phrase ('Live balance lookup', 'hits Plaid, not cached', 'Filter by account_id if given') adds distinct value without redundancy.

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 tool's moderate complexity (single optional parameter, external API calls), no annotations, and an output schema (which handles return values), the description is minimally adequate. It covers the core purpose and parameter use but lacks details on error cases, performance implications, or integration with sibling tools.

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 description adds meaningful context for the single parameter: 'Filter by account_id if given' clarifies its optional filtering purpose. With 0% schema description coverage and no parameter documentation in the schema, this compensates well. However, it doesn't specify the account_id format or constraints.

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: 'Live balance lookup' specifies the verb and resource, and '(hits Plaid, not cached)' adds technical context. However, it doesn't explicitly differentiate from sibling tools like 'list_accounts_tool' or 'get_holdings_tool' beyond the balance focus.

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 some usage context: 'Filter by account_id if given' implies optional filtering, and 'hits Plaid, not cached' suggests real-time data needs. However, it lacks explicit guidance on when to use this versus alternatives like 'list_accounts_tool' or 'get_holdings_tool', and doesn't mention prerequisites or exclusions.

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