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

With no annotations supplied, the description carries the full burden and does most of it: it discloses the return payload in detail (manifest hash, per-tool hash, added/removed/changed diff, Unicode findings scoped to name/description/schema strings) and describes the output as reproducible, implying determinism. It does not explicitly say the tool performs no network fetches or writes (i.e., that it only analyzes the payload you hand it), which is the one behavioral fact an agent still has to infer.

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?

The core capability and the input shape are front-loaded in the opening clause, and the parenthetical about silent description/schema edits justifies the tool's existence rather than padding it. The definition loses a point for the truncated final sentence ('Call it at sessi'), which leaves a dangling instruction the agent must guess at.

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 three-parameter tool with no output schema and nested object inputs, the description compensates well by enumerating every return field and naming the threat model. The missing pieces are the truncated call-timing instruction and any note on how to interpret or act on a positive diff finding.

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 baseline is 3, and the description earns a bump by explaining the temporal relationship between the three parameters: `tools` on the first call, then `approvedTools` and `approvedManifestHash` from the call you approved. That is genuine meaning beyond the schema's per-field text, though it doesn't clarify what happens if only one of the two approval parameters is supplied.

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 first sentence names a specific verb+resource pair ('detect changed tool definitions') and two distinct capabilities (rug-pull diffing and hidden Unicode detection), plus the exact input it consumes ('an MCP server's tools/list result'). An agent can tell this apart from any hashing or audit sibling 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 establishes the invocation pattern clearly: first call with just `tools`, subsequent calls with the previously approved hashes, and a stated trigger ('Call it at sessi…' — truncated, presumably session start). What's missing is any explicit statement of when NOT to use it or what to do when a diff reports changes, but the operating context is otherwise unambiguous.

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