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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds real context by naming the authoritative source ('official directory') and the 'active listing' condition, but it does not say what a result looks like (boolean vs. detail record) or how name matching behaves.

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?

One front-loaded sentence with no filler and nothing redundant. It is efficient, though the brevity leaves gaps that a second short sentence could have closed.

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?

This is a low-complexity, single-parameter, read-only tool with full schema coverage and no output schema, so the burden is light. Still, the description never indicates the shape of a verification outcome or the failure mode for unlisted/uncertified names, which is the main thing an agent needs before calling it.

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?

With one parameter at 100% schema coverage, the schema already defines 'name' as the instructor's full name. The description adds nothing about matching strictness, formatting, or handling of duplicates and partial names, so it stays at the baseline.

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 (checks/verifies) and a specific resource (Pilates+ certified instructor status in the official directory), including the 'active listing' criterion. It implicitly contrasts with find_pilates_plus_instructor (verify a known person vs. discover instructors) but never names that sibling, so differentiation is inferable rather than explicit.

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: you supply a person's name to confirm certification. There is no statement of when to prefer this over find_pilates_plus_instructor, no note on prerequisites, and no guidance for the ambiguous case of a name that returns no match.

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