people_from_image

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It does useful work by disclosing the output contract ('outcome, normalized output, raw provider data and _meta.tried') and the cost model ('Provider API charges are billed directly to your provider account'). It does not mention auth, rate limits, or failure behavior, but for a search-style tool the disclosed billing and raw-data behavior are meaningful.

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 concise and front-loaded with the tool's purpose. It delivers the key output and billing facts in four short sentences with no filler. Slight jargon like '_meta.tried' and 'normalized output' is acceptable because it matches the output schema.

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?

The description covers purpose, output shape, vendor pinning, and billing, and an output schema exists to document return values. However, it omits usage routing versus siblings and leaves the primary image_url parameter under-explained. For a tool with no annotations and a meaningful sibling set, this is adequate but not complete.

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 67%: vendor and waterfall are documented, while image_url has an empty schema description. The description reinforces vendor selection but does not clarify the core image_url input or its expected format. The parameter name and the phrase 'Where a photo appears' make the intent inferable, so this is a moderate gap rather than a severe one.

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 identifies the tool as a reverse-image lookup: it finds web pages carrying an exact image and the social profiles among them. It uses descriptive phrasing rather than a verb like 'find', but the resource and outcome are unmistakable. It does not explicitly differentiate itself from the sibling social_profile tool, but its image-based input and page-plus-profile output distinguish it in practice.

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 no guidance on when to choose this tool over siblings such as people_search, social_profile, or people_identity_resolve. The only directive, 'Use vendor to pin a provider', is operational parameter guidance rather than use-case guidance. There is no mention of when this tool is appropriate or when an alternative should be used.

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