Update Sieve script

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

No annotations are provided, so the description carries the full burden. It discloses a key behavioral trait: 'The whole script is replaced', which is critical for an update operation. It also mentions the RFC syntax, though it does not detail permissions or error behavior; for a simple replacement, this is sufficient.

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 with no filler. The main action is front-loaded, and the second sentence provides a crucial caveat about fetching the current script first. Every word earns its place.

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 two-parameter update tool with no output schema, the description fully covers the essential context: what the tool does, the destructive replacement behavior, and how to safely modify rules by referencing the sibling tool. It is complete for its 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?

Schema coverage is 100%, so the baseline is 3. The description adds contextual meaning by implying the script parameter represents the complete replacement and that the address is the full mailbox address, reinforcing the replacement semantics beyond what the schema states.

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 uses the specific verb 'Replace' and clearly identifies the resource as 'the Sieve filtering script of a mailbox', which distinguishes it from siblings like get_mailbox_sieve and update_mailbox. It also specifies the RFC 5228 syntax, adding precision to the tool's purpose.

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?

It explicitly states that the whole script is replaced and advises fetching the current one with get_mailbox_sieve if only adding rules, providing clear when-to-use guidance and naming the alternative tool for partial modifications.

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