Update alias

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

With destructiveHint already true, the description still adds real value: partial-update semantics ('Only the provided fields change'), validation behavior ('a call that changes nothing is rejected without contacting SimpleLogin'), and the concrete destructive consequence ('Replacing mailboxes can stop future mail from landing in removed mailboxes'). That is specific consequence disclosure rather than restating annotations.

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?

A single front-loaded paragraph with no filler sentences; each clause carries a constraint or consequence. Slight redundancy in re-listing the field names already documented in the schema, which keeps it from a 5.

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 7-parameter mutation tool with no output schema, it covers partial-update behavior, argument exclusivity, no-op rejection, and the destructive mailbox effect. It stops short of error/auth behavior (e.g. invalid alias_id or nonexistent mailbox ids), but the essentials for a correct call are present.

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 goes beyond it by declaring the mailbox_id/mailbox_ids mutual exclusion and clarifying that only supplied fields are replaced, semantics the schema descriptions do not state.

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?

States a specific verb (update) and resource (existing alias) and enumerates the mutable fields. It is clearly distinguishable from siblings like alias_create_random, alias_delete, and alias_set_enabled without opening a schema.

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?

Gives a concrete precondition ('Provide at least one field to change') and a no-op rejection rule, plus the mailbox_id/mailbox_ids exclusion. It does not, however, route the agent to alternatives such as alias_set_enabled for toggling enablement, which is the main missing usage cue.

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