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

No annotations are supplied, so the description carries the full behavioral burden. It usefully discloses the auth model ('Uses the workspace key from your MCP server URL') and implies mutation, but never states whether changes are persisted, whether they apply only to future redactions or retroactively, or whether the detectors map merges with or replaces existing settings — a critical ambiguity for a config-mutation tool.

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 tight sentences, front-loaded with the action and then the three capability branches, each with a concrete example. Minor filler in 'right from your chat' that does not earn its place, but no structural waste.

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 no-annotation, no-output-schema mutation tool with a nested-object parameter, the definition omits the essentials: what the call returns, whether the change is idempotent, and how partial updates behave. It covers what can be changed but not the consequences of changing 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?

Schema description coverage is 100%, so the schema already documents all four parameters; the description's detector and regex examples largely restate the schema's own examples. The one added signal is the note that shield_key is normally unnecessary because the key comes from the URL, but merge-vs-replace semantics for the nested detectors object remain undefined.

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: 'Change what this workspace masks', and enumerates the three editable dimensions (detector toggles, always-mask terms, custom regex PII). It is clearly distinguishable from read-side siblings like get_coverage and list_detectors, though it never names those siblings explicitly.

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: the agent can infer this is the write counterpart to get_coverage when masking configuration must be altered. There is no explicit when-to-use statement, no prerequisite chain (e.g. call list_detectors first to learn valid detector names), and no guidance on whether to read current coverage before changing it.

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