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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is covered. The description usefully adds that tokens are reversible and gives the POST endpoint, but says nothing about auth/API-key requirements, whether tokens or mappings are persisted server-side, expiration, or rate limits.

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?

A single front-loaded sentence plus a parenthetical endpoint; no wasted words and the capability is stated first. It is efficient, though the brevity leaves little room for the operational details an agent might need.

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 simple two-parameter tool with no output schema, the description covers what it does but not what comes back — e.g., whether the response is redacted text only or text plus a token mapping needed for later re-identification. That return-shape question matters for a reversible-masking tool and is left unanswered.

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% with only two parameters, so the baseline is 3. The description adds no meaning about 'mode' (its only schema hint is an example value 'token'), nor about whether 'text' is processed whole or chunked, so it does not improve parameter understanding beyond structured fields.

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 ('Mask') plus concrete resource types (emails, phones, IBANs, cards, EU IDs) and the mechanism (reversible tokens), which lets an agent distinguish it from siblings like tinplate_eu_id_validator or tinplate_secret_scanner. It stops short of explicitly naming which sibling to use instead for adjacent tasks, so it is clear but not maximally differentiated.

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 LLM calls' implies a usage context, but there is no explicit when-to-use/when-not-to-use guidance and no named alternative (e.g., a validator or scanner sibling) for cases where you only need detection rather than reversible masking. The endpoint note is operational, not routing guidance.

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