list_blocked_senders

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

There are no annotations, so the description carries the full burden. It discloses that the tool lists all filters, not just blocked senders, which is a useful behavioral trait beyond the name. However, it does not mention return format, pagination, or any read-only guarantee, leaving some gaps.

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 two sentences long, with the first sentence stating the core purpose and the second providing usage guidance. Every word adds value, with no filler or redundant content.

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 simple list tool with one parameter and no output schema, the description is fairly complete: it explains what is listed, the scope, and common use cases. However, it could be more explicit about the structure of the response, but this is minor given the tool's simplicity.

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 only parameter 'account' is already described in the schema with 'Account id.' The description adds no additional parameter semantics, but since schema coverage is 100%, the baseline of 3 is appropriate.

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 lists all Gmail filters for an account, which is specific and distinguishes it from sibling tools like list_accounts or get_labels. It also clarifies the relationship to blocked senders, explaining that blocked senders are represented as filters, and provides a concrete use case (finding filter_id for unblock_sender).

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 explicitly says when to use this tool: to find filter_id for unblock_sender or to audit auto-trashed/archived/spammed content. It gives clear context but does not explicitly state exclusions or alternatives, hence a 4 rather than 5.

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