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

The description discloses critical behavioral traits beyond the readOnlyHint annotation: images enter the model's context, the server runs no image analysis itself, videos return as cover frames, and metadata (time and place) is attached. This tells the agent exactly what to expect from the call and how to interpret results.

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?

Three tight, front-loaded sentences cover purpose, usage, and behavior with zero redundancy. Every sentence earns its place, and the most important information (what the tool does) leads off.

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 no output schema, the description sufficiently explains what the agent receives (images, metadata, cover frames) and how to request them (media_ids or trip_id). It also states the no-analysis limitation, which is critical for the agent to know it must interpret images itself. Nothing essential is missing.

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%, so the baseline is 3. The description adds minor value by explaining the relationship between media_ids and trip_id ('Name specific media_ids, or give a trip_id to pull a batch') and the concept of batching, but does not add significant meaning beyond what the schema already defines.

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 starts with 'Look at the pictures themselves' – a specific verb and resource – and clarifies that it returns actual media content with time and place attached. This distinguishes it from listing tools like list_media (metadata only) and conveys its core function clearly.

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 gives clear usage instructions: name specific media_ids or provide trip_id for a batch, and notes the 'filter' option with trip_id. While it implies this is for viewing actual content ('you can only describe what you have seen'), it does not explicitly name alternatives or state when not to use this tool, leaving some inference to the agent.

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