photos_list_timeline

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

Annotations already declare readOnlyHint and idempotentHint, providing safety and idempotency. The description adds value by disclosing the default return format ('Returns [{nodeUid}] by default'), the optional behavior with loadDetails ('pass loadDetails=true for full node metadata'), and performance implications ('slower; buffers the whole list in memory first'). This goes beyond what annotations provide.

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 description is three sentences long, front-loaded with the core purpose, then provides auth requirement, return format, parameter behavior, and alternatives. Every sentence adds necessary information with no redundancy. It is concise yet comprehensive.

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?

Given the tool's simplicity (one optional parameter), strong annotations, and absence of an output schema, the description adequately covers the essentials: what it lists, what it returns by default, what happens with loadDetails, authentication, and related tools. No critical information appears missing for an agent to select and invoke this tool 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?

The input schema already documents loadDetails with its meaning and default. The description adds extra context by explaining the performance and memory trade-offs ('slower; buffers the whole list in memory first') and reiterates the default return format. This enhances the schema description, so a score above baseline is warranted.

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 clearly states the tool's function: 'List photos in your Proton Photos timeline' with the explicit caveat '(your full photo library, not scoped to an album)' which distinguishes it from album-scoped siblings like photos_list_album_photos. The verb 'List' and resource 'photos in your Proton Photos timeline' are specific and unambiguous.

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 provides explicit guidance on when to use this tool versus alternatives: 'Use photos_download to download items by path, or photos_add_to_album to add them to an album.' It also clarifies the scope ('not scoped to an album'), implying when to choose this over album-specific listing tools. This is clear and directly addresses alternatives.

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