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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safe, deterministic character of the call is covered. The description adds useful domain context (what a complete profile consists of), but says nothing about the shape of the response or how results are grouped, which matters because no output schema exists. Adequate but thin beyond the annotations.

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?

Three short sentences, front-loaded with the selection criterion, then the profile-completeness model, then the input-source hint. The first sentence is a noun fragment rather than a verb phrase, and the middle sentence reads as background rather than call guidance, but nothing is wasted.

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 read-only, closed-world, zero-required-parameter tool with fully documented params and rich annotations, the basics are covered. The gap is the missing description of what comes back (styles grouped per photo type, and example images when show_previews is set), which the agent must infer since there is no output schema. That omission keeps it at minimum-viable completeness.

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 description coverage is 100%, so all three parameters are already documented, including the enum of photo types and the 1-6 bound on per_type. The description adds only the framing of where the 'missing' values should come from (the photo check), without explaining defaults, the effect of an empty list, or how show_previews interacts with per_type. Baseline 3 is appropriate when the schema carries the parameter burden.

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?

"Styles that fill the photo types a dating profile is missing" names the resource (styles) and the selection criterion (photo types the profile lacks), and enumerates the six target categories so the agent knows exactly what a result set covers. It implicitly contrasts with list_styles (unfiltered enumeration) but never names that sibling, so the differentiation is inferable rather than stated.

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 the photo check's missing list when you have it" gives a concrete trigger and an implied fallback path (call it without the list), and points the agent toward get_photo_check as the source of that input. However, it never states when to prefer this over list_styles or what happens semantically when 'missing' is omitted versus empty, leaving the main alternative-selection question unanswered.

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