Read the permissions an extension has been granted

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

With readOnlyHint already declared, the description adds strong context beyond annotations: it identifies the readable permission and origin string arrays, explains that the surface is available without opening about:addons, and clarifies that granting/revoking is extension-owned UI.

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 description is short, front-loaded with the core action, and each sentence adds useful information: purpose, readable output shape, and the read-only limitation. There is no wasted framing.

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 read-only tool with full schema coverage and no output schema, the description is complete enough: it explains what is returned, what is not done, and why the read is possible. No important agent-facing gap is apparent.

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%, and the single optional id parameter is already documented in the schema. The description does not add parameter-specific meaning beyond that, so the baseline of 3 is appropriate.

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 states a specific verb and resource: reporting user-granted permissions and origin patterns of installed extensions. It also distinguishes the read-only permission surface from granting/revoking permissions, so the agent can tell it apart from mutation-oriented permission tools.

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 clearly explains the context: use this to inspect granted permissions and origins, and it explicitly notes that this tool does not grant or revoke permissions. It does not name specific alternative sibling tools, so it falls short of full when-to-use/when-not/alternatives guidance.

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