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

Annotations already declare readOnlyHint and openWorldHint, so network access and safety are covered structurally; the description adds real value by enumerating the specific threat categories it screens for. It does not describe what the scan returns or how findings are reported, and it leaves the rate-limit information entirely to the schema.

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, both front-loaded: the first gives the when-and-why, the second gives the how. Every clause carries information and there is no filler.

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 read-only audit tool with no output schema, the definition never indicates what a scan produces (verdict, findings list, risk score) or how to act on the result, which is the main thing an agent still needs to infer. Inputs and trigger are otherwise fully covered.

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 all three parameters, including the api_key limit raise, are already documented in the schema. The description's line 'Pass the server's URL, or its tools/list result' restates the either/or choice already implied by the schema's 'Or:' prefixes, adding little new meaning.

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 names a specific verb and resource ('check its tool descriptions') and defines the exact failure mode it detects ('tool poisoning'), listing concrete red flags such as reading credential files or hiding actions. It is clearly distinguishable from siblings like check_url or fetch_safely, which do not audit tool definitions.

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 states the trigger condition explicitly: 'Before connecting to a new MCP server.' It also clarifies the two accepted input modes (URL vs. tools/list result). It does not name an alternative tool or state when not to use this one, which keeps it short of a 5.

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