Access Status

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

Beyond readOnlyHint=true, it discloses that enforcement happens at dispatch outside the model and that local stdio reports `enforced: false` — a caveat that directly affects how much an agent should trust the result. It stops short of stating what happens to blocked calls or how the reported scope interacts with retries, but the key behavioral nuance is covered.

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, front-loaded with the core purpose, followed by the enforcement caveat. Every clause carries information; nothing is repeated from the annotations or the empty schema.

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?

With no parameters, no output schema, and a read-only annotation, the description carries the return-value burden and does so by enumerating the reported fields and the `enforced` flag. It leaves the shape/format of those fields implicit, a minor gap for an otherwise simple tool.

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?

The tool takes zero parameters, and the description correctly introduces none, so there is no semantic gap to fill. It adds context about which caller's policy is reported ('the calling hosted key'), which is the only input-like distinction that matters here.

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 ('Report the calling hosted key's effective access policy') and enumerates exactly what that policy contains: allow/deny globs, task scope, expiry, and currently callable tools. That subject matter cannot be confused with any sibling such as core.health, core.compatibility, or core.version, so an agent can select it 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?

Usage is only implied: an agent infers it should call this to learn its own permissions before attempting gated actions. The description never states when to call it versus letting dispatch simply fail, nor names any alternative (e.g. core.compatibility) for related checks.

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