Firefly III MCP Server

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

Annotations already declare readOnlyHint=true, destructiveHint=false, and idempotentHint=true. Description adds valuable behavioral context about return values ('Returns full details including all splits') which compensates for missing output schema. No contradictions with 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?

Two sentences, zero waste. First sentence establishes core operation; second sentence adds critical return value detail. Efficiently front-loaded with no filler.

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?

Appropriately complete for a simple 1-parameter read operation. Mentions 'splits' (key domain concept) to clarify return structure despite lack of output schema. Could explicitly note that ID refers to transaction group (though schema covers this).

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?

Schema coverage is 100% with 'Transaction group ID' documented. Description reinforces usage pattern ('by its ID') but does not add significant semantic meaning beyond the schema. Baseline 3 appropriate when schema carries full documentation burden.

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?

Clear specific verb ('Get') + resource ('transaction') + scope ('single'). Distinguishes from siblings firefly_list_transactions and firefly_search_transactions by emphasizing 'single' and domain-specific detail 'including all splits' (critical for Firefly III's split transaction model).

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?

Implies usage constraint through 'by its ID' (suggests you must know the specific ID), but lacks explicit when-to-use guidance versus alternatives like firefly_search_transactions or firefly_list_transactions. No mention of prerequisites for obtaining the ID.

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