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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false. The description adds the non-obvious behavioral fact that this is a qualitative checklist rather than the scored evaluation, which prevents the agent from presenting its output as an official score. It does not describe the checklist's structure or length, keeping it a notch below full transparency.

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?

Two short sentences, both load-bearing: the first defines the artifact and its scope, the second redirects to the official scored check. The scope constraint is front-loaded and there is no redundant restatement of the title.

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 zero-parameter, read-only guidance tool with annotations covering the safety profile and no output schema needed, the description supplies enough to call it correctly and to route users elsewhere for scoring. A brief indication of what the checklist covers (or that its text is returned verbatim for the agent to relay) would make it fully self-contained.

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 tool takes no parameters, so there is nothing for the description to disambiguate and the baseline of 4 applies. Nothing in the description misstates or adds conflicting parameter expectations.

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 names the resource concretely ('checklist for reviewing dating profile photos') and scopes it to photos shared in chat before account creation. It also differentiates itself from the scored-check sibling by stating that the official scored photo check runs on truelook.app, so an agent can tell which surface performs scoring. The only gap is that 'photo_review_guide' does not restate a verb, leaving it slightly implicit that this returns guidance rather than analysis.

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 phrase 'before they have an account' and 'the official scored photo check runs when they upload on truelook.app' together give a clear routing condition: use this for pre-signup, in-chat photo feedback, and defer scored checks to the app. It does not add explicit exclusions (e.g., what to do for users who already have an account), so it falls short of a full when/when-not statement.

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