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

Annotations already convey destructiveHint=true and readOnlyHint=false, lowering the burden on the description. The description adds useful context about what is deleted and that it must be an existing attachment, but it does not disclose permanence, cascading effects, or any post-deletion behavior. It meets the baseline but does not go beyond it significantly.

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 tight sentences that front-load the core usage condition and immediately follow with an exclusion. Every sentence earns its place; there is no filler or redundancy.

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 destructive operation with one required parameter, an output schema, and annotations covering the destructive nature, the description plus schema and annotations is fully sufficient. It tells the agent exactly when to invoke the tool and what it acts on.

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 input schema already documents both parameters well: attachmentId is described as the Familia attachment id to delete, and timezone as the IANA timezone. The description adds no additional parameter-level meaning, so the baseline of 3 applies.

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 ('delete or remove'), a specific resource ('existing Familia photo, checklist, or list attachment'), and clearly distinguishes this from related operations. The scope is clear enough that an agent can differentiate it from sibling tools like familia_delete_plan or familia_update_list_attachment.

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?

Explicitly says when to use the tool ('only when the user explicitly asks to delete or remove') and when not to use it ('Do not use for hiding or summarizing attachments'). This gives clear positive and negative triggers with no reliance on inference.

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