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

Annotations already cover safety (readOnly, idempotent, non-destructive, closed-world), and the description adds what they cannot: it is free with no account, payment or credits required, and the content is a clearly fictional, annotated example from a published article, not a real customer or proof of improved matches. These cost/auth preconditions and content disclaimers are exactly the extra context an agent needs before presenting 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?

Front-loads the free/no-account precondition, then the when-to-use trigger, then the content description and a compact list of things the result is not. Four tight sentences with no filler, though the negation list is dense and could be trimmed to one clause.

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 only two enum parameters, full schema coverage and no output schema, the description still tells the agent what comes back (an annotated example bio and photo lineup), in which languages, at what cost, and what the result must not be represented as. Nothing material is missing for correct invocation.

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 100%, so 3 is the baseline, but the description adds intent beyond the enum values: it explains locale as the response language (English or French) and reinforces that persona must be chosen from what the user actually asked for rather than inferred. That selection rule adds behavioral meaning the schema only partially encodes.

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 verb and resource — retrieves a fictional, annotated example profile (bio plus photo lineup) in English or French — and explicitly negates adjacent capabilities it is not (image analysis, evidence of improved matches), which separates it from siblings like score_photo_observations and get_photo_guidance. It stops short of naming those siblings directly.

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?

"Use when asked for an example bio and photo lineup for a single dad or someone returning to dating" gives a clear triggering condition, and "Choose only the persona requested by the user" constrains selection. No alternative tools are named, so routing when the user wants guidance rather than an example is left implicit.

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