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

With no annotations, the description carries the full burden; it does establish that the operation is a read ("Show") and discloses the auth model — the workspace key is taken from the MCP server URL. It does not state that nothing is modified, nor anything about response format or latency, so the behavioral picture is partial.

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 short sentences with no filler: the resource and its contents come first, the credential sourcing second. Nothing could be removed without losing information.

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 zero-required-parameter read tool with no annotations and no output schema, the description covers what is inspected and how authentication is resolved, which is enough to call it correctly. Only the explicit relationship to set_coverage 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 100%, so the shield_key parameter is already documented, but the description adds genuine meaning by explaining where the key normally comes from (the MCP server URL), clarifying when the optional override is needed. This is a modest but real addition over the schema text.

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?

"Show your workspace's current PII coverage" gives a specific verb and resource, and the parenthetical enumerates exactly what is returned (detectors on, custom terms, custom patterns), which separates it from list_detectors and detect_pii. It does not explicitly name set_coverage as its write counterpart, so the read/write distinction is only implied by "current" and the verb.

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 word "current" and the inspection framing imply this is the read-side counterpart to set_coverage, but no alternative is named and no when-to-use or when-not-to-use condition is stated. An agent can infer the routing but is not told it.

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