Firefly III MCP Server

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

While annotations declare destructiveHint=true, the description adds critical behavioral specifics: the cascading deletion of linked transactions and explicit irreversibility warnings. These details about side effects go beyond the boolean annotations.

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?

Three sentences, each earning its place: action definition, cascade warning, and irreversibility notice. Information is front-loaded with the primary action stated first.

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 single-parameter destructive operation with clear annotations, the description adequately covers the action, side effects, and permanent nature. No output schema exists, but the description sufficiently prepares the agent for the operation's consequences.

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?

With 100% schema description coverage ('Account ID to delete'), the schema fully documents the single parameter. The description does not add additional semantic context about the ID format or validation rules, meeting the baseline expectation.

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 states a specific verb ('delete') and resource ('account'), clearly distinguishing it from sibling tools like firefly_delete_budget or firefly_delete_transaction. The scope is immediately obvious.

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 warns about consequences ('cannot be undone', 'linked transactions will also be deleted') which implicitly signals when to use caution, but provides no explicit guidance on when to choose deletion over firefly_update_account or other alternatives.

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