photo_info

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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, so the safety profile is clear. The description adds little beyond the annotations, only hinting at the breadth of data ('everything known'), but doesn't disclose potential privacy implications or rate limits. No contradiction.

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 two sentences: one functional summary and one parameter explanation. No wasted words, and the key action and resource are front-loaded.

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 single-parameter read-only tool with rich annotations and an output schema (not shown), the description covers what the tool returns and how to specify the target photo. It lacks guidance on when to choose this over siblings, but overall it is sufficiently complete for an agent to invoke 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 0%, so the description must carry the burden. It does by explaining that 'refs' are 'Photo uuids or exact filenames', which is far more informative than the schema's bare 'Refs' title. This effectively compensates for the lack of schema 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 uses a specific verb 'Everything known' and lists the exact kinds of information (metadata, ML labels, place, albums, faces, text), making it obvious that this tool retrieves comprehensive metadata for a given photo. It is clearly distinct from siblings like search_photos or look_at_photos.

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 states what the tool does but does not explicitly say when to use it over alternatives. It implies usage for retrieving detailed photo information, but there is no mention of exclusions or comparisons to look_at_photos/edit tools.

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