Block/unblock alias contact

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

Annotations already declare idempotentHint=true, destructiveHint=true, and readOnlyHint=false, so the mutation/safety profile is covered. The description adds genuine value beyond that: it explains why alias_id is required (reading current state first), confirms a same-state call is a no-op, and states the returned block_forward field, which no output schema provides.

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 three sentences are front-loaded with the core action, then usage semantics, then the requirement and return value. Every sentence earns its place and nothing is redundant.

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 3-parameter mutation tool with no output schema, the description supplies the missing pieces: the reason for the required alias_id, the no-op idempotent behavior, and the return field. Combined with annotations covering the safety profile, an agent has everything needed to call it correctly.

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, and the schema already documents all three parameters. The description goes further by explaining the semantic role of alias_id (the contact belongs to it, needed for the read-before-write) and the boolean's meaning, adding meaning beyond the field descriptions.

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 names a specific operation (set/unset forwarding block from a contact to its alias) with a clear verb+resource. It is unambiguous and distinct from the surrounding contact_list/contact_create/contact_delete siblings, though it does not explicitly reference any of them for contrast.

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 clearly states how to use the tool by mapping blocked=true/false to the intended outcome (stop mail vs. allow it) and explains the no-op case. There is no explicit 'when-not' guidance and no alternative is named, but no real alternative exists among the siblings, so the context is adequately clear.

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