Firefly III MCP Server

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

Annotations already declare idempotentHint=true, destructiveHint=false, and openWorldHint=true, covering safety and idempotency. The description adds that it updates 'name, status, or notes,' but since schema coverage is 100%, this adds minimal value. It fails to clarify critical behavioral details like partial update semantics (only provided fields are changed) or error handling when the budget ID does not exist.

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 consists of a single, efficient sentence with nine words that front-loads the action verb. There is no redundant or wasted text; every word serves to define the tool's scope.

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 simple 4-parameter schema with 100% coverage and comprehensive annotations, the description provides adequate context for basic usage. However, for a mutation tool, it lacks important operational context such as confirmation that omitted fields remain unchanged, potential validation errors, or side effects on related transactions.

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, the baseline score is 3. The description lists the updatable fields (name, status, notes) but does not add semantic meaning beyond what the schema already provides, such as constraints on name uniqueness, format expectations for notes, or clarification that 'status' refers to the 'active' boolean field.

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 verb (Update), resource (budget), and specific fields affected (name, status, notes). The word 'existing' effectively distinguishes this from the sibling firefly_create_budget tool, though it does not explicitly name alternatives.

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 phrase 'existing budget' implies this should be used for modifying current budgets rather than creating new ones, providing implied usage context. However, it lacks explicit guidance on when to choose this over firefly_create_budget or firefly_delete_budget, and does not mention prerequisites like obtaining the budget ID first.

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