Is this key safe to expose?

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

Beyond the readOnlyHint/idempotent/closed-world annotations, the description discloses that classification is done offline with no network calls and that the full key is never echoed back — exactly the behavioral traits that matter for a credential-handling tool. It also flags the security-relevant next step (rotate if secret).

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 sentences, no waste. It front-loads the core classification behavior, then the safety instruction about what to pass and what not to send. Every clause earns its place.

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 single-parameter tool with no output schema, the description covers the input contract, the output semantics (public-by-design vs secret, with examples), the recommended action, and the privacy behavior. Nothing needed to invoke it correctly is missing.

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 already 100% and the single parameter's description restates the prefix guidance, so the baseline is 3. The description adds value by tightening the contract — 'Pass ONLY the prefix (first 8-15 characters), never the whole key' — which clarifies intent and privacy constraints beyond the schema's softer 'a prefix is enough'.

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 states a specific verb and resource: classify an API key as public-by-design vs secret, offline from its format. It names concrete examples of each class (Supabase anon/publishable, Stripe pk_ vs sk_live_, service_role, sk-ant-), so the agent knows exactly what this tool returns without opening the schema.

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?

It gives clear operational context and a follow-up action ('rotate first if secret'), which is real guidance. It does not, however, contrast itself against the siblings (supabase_rls_audit_sql, rls_policy_template, vibe_security_checklist, scan_my_app_instructions), so an agent choosing among the security tools gets no explicit routing.

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