create_gmail_filter

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

With no annotations provided, the description carries the full burden of disclosing behavioral traits. It states the return value (confirmation message with filter ID) but does not mention permissions, reversibility, idempotency, error behavior, or side effects. This is inadequate for a mutation tool.

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 well-structured with Args and Returns sections, and every sentence is purposeful. It is concise and front-loaded with the core purpose. Minor redundancy with schema types but overall efficient.

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?

The tool has nested objects (criteria and action) with complex structures, but the description provides no details or examples on how to construct them. It does not explain valid fields or formats, leaving the agent under-informed. The return value is specified, but the input construction is insufficiently described.

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 meaning beyond the schema: for user_google_email, which has no schema description, it clarifies it is the user's Google email and required. For criteria and action, it provides plain-language explanations ('Criteria for matching messages', 'Actions to apply to matched messages') that complement the vague schema descriptions. Schema coverage is 67%, and the description helps compensate.

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 action: 'Creates a Gmail filter using the users.settings.filters API.' It specifies the exact resource and API, distinguishing it from siblings like list_gmail_filters and delete_gmail_filter. The verb 'creates' is specific and unambiguous.

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 no guidance on when to use this tool versus alternatives. It does not mention prerequisites, exclusions, or scenarios where another tool might be more appropriate. Usage is only implied by the purpose statement.

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