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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safe-read profile is covered structurally. The description adds modest value by clarifying that the tool serves as an ID-discovery step before edits, implying attachment IDs are returned, but it adds no deeper behavioral detail such as pagination or filtering behavior.

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, both earning their place: the first states the main use case, the second states a secondary workflow trigger. The most important scoping information is front-loaded and there is zero filler.

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?

With an output schema present and 100% parameter schema coverage, the description does not need to explain return values or parameter formats. For a low-complexity read-only list tool, the description plus structured fields cover what an agent needs; it omits only minor context like whether results are ordered or limited.

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 description coverage is 100%, with targetType, targetId, and timezone each documented in the schema itself. Per the rubric, high schema coverage sets a baseline of 3, and the description adds no parameter-level meaning beyond what the schema already provides.

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 verb and resource — 'list attachments' on an existing Familia task or plan — and further scopes it to 'photos, checklists, or list attachments' so an agent knows exactly what is returned. This scope clearly differentiates it from siblings like familia_search_items or familia_get_inbox.

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 gives an explicit trigger condition ('when the user asks what photos, checklists, or list attachments are attached') and a workflow rule ('Use before editing an existing list attachment when the attachment id is unknown'). It doesn't explicitly name when-not-to-use it or contrasting alternatives, but the guidance is concrete enough to route correct invocation.

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