Certificate exceptions

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

Annotations already cover the read-only safety profile, and the description adds genuinely new context: the exact fields returned (host, port, flags, temporary flag) and the fact that temporary exceptions vanish when Firefox exits. It does not mention enumeration limits or whether expired/revoked entries are excluded, which keeps it off a 5.

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?

Three sentences, front-loaded with what is listed and what fields come back; the usage scenarios follow and the ephemerality note last. Every sentence carries information, though the parenthetical API name is slightly redundant detail for an agent caller.

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?

There is no output schema, so the description's inline field list (host, port, flags, temporary) usefully stands in for one, and the 'disappear on exit' note tells the agent how to interpret the temporary flag. Adequate for a simple read-only enumerator.

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, so there is nothing for the description to disambiguate; baseline for a no-arg tool is 4. The description correctly implies the result is unfiltered and account-wide rather than scoped to a tab or host.

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?

Uses a specific verb ('List') plus a precise resource ('TLS certificate exceptions the user has accepted') and even names the underlying API (nsICertOverrideService.getOverrides), so there is no ambiguity about what is returned. It does not name the most confusable sibling (browser_relax_certificate_checks, browser_certificate_manage), which is the only thing separating it from a 5.

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?

Gives two concrete situations that select this tool: confirming a test site was trusted, and auditing that nothing unexpected was accepted. It stops short of naming alternatives or stating when not to use it (e.g. use browser_relax_certificate_checks to add an exception rather than read one).

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