Mariana Google MCP

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

With no annotations provided, the description carries the full burden of disclosure. It successfully communicates the critical side effect regarding notification defaults but omits other important behavioral details such as partial vs. full replacement semantics, error handling for invalid event_ids, or idempotency guarantees.

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 two highly efficient sentences. The first states the purpose; the second delivers a critical behavioral warning. Every word earns its place with no redundancy or fluff.

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 9-parameter mutation tool with no output schema and no annotations, the description covers the essential action and safety-critical notification behavior but remains minimal. It adequately serves the complexity level but would benefit from mentioning error conditions or return value structure.

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?

Input schema has 100% description coverage, establishing a baseline of 3. The description adds contextual meaning to the 'send_updates' parameter by emphasizing the user impact of the default (false) setting, but does not add significant semantic value beyond what the schema already documents for the other 8 parameters.

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 core action ('Modify') and resource ('existing calendar event'), with 'existing' effectively distinguishing it from the sibling 'calendar_create'. However, it does not explicitly name sibling alternatives or clarify partial vs. full update semantics.

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 a critical usage hint regarding attendee notifications ('Does NOT notify attendees by default'), which guides the agent on when to explicitly set the 'send_updates' parameter. However, it lacks explicit guidance on when to use this tool versus 'calendar_create' or other siblings.

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