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

Annotations already declare readOnlyHint, idempotentHint, non-destructive and closed-world, so the safety profile is covered. The description adds useful context – it is a free check over previously uploaded selfies – but leaves a key behavioral question open: whether this only fetches an existing result or triggers computation, and what happens when no check exists yet. With annotations carrying the safety burden, a 3 is appropriate.

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?

A single dense sentence front-loads the identity of the result and then enumerates its contents, followed by a short instruction sentence. Every clause carries information, though the long enumeration list makes it slightly run-on.

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?

There is no output schema, so the description appropriately enumerates the return payload, which is exactly what an agent needs. The remaining gap is state behavior – error or empty-result handling when no photo check has been run – plus no explicit sibling routing, keeping it below 5.

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?

Only one parameter, and schema coverage is 100% with a self-contained description of connection_key including the 'never show it to the user' warning. The tool description adds nothing about connection_key, so the baseline 3 applies; the schema does all the work here.

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?

States a specific resource (the DatingProfile photo check of uploaded selfies) and enumerates exactly what it returns: overall score, potential, five category scores with findings, per-photo notes, and missing photo types. That makes it distinguishable from get_photos (raw photos) and create_photos. It does not, however, distinguish itself from photo_review_guide or recommend_styles, which sound adjacent, so it falls short of a 5.

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?

Usage is only implied: the tool applies to selfies the user already uploaded, and the description instructs to 'explain it... then suggest styles for what is missing' – loosely routing to recommend_styles. There is no explicit when-to-use or when-not-to-use versus get_photos, photo_review_guide, or recommend_styles, and no stated prerequisite (e.g. that a check must already exist).

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