explain_certificate

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

With no annotations provided, the description carries the full burden and does well: it states 'Computes nothing new; it re-presents the arithmetic the verdict already rests on,' disclosing the read-only, non-mutating nature. It could add more about output formatting or errors, but the key behavioral trait 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?

Three dense sentences, front-loaded with the core verb ('Explain WHY a certificate reached its verdict'). Every sentence adds value: purpose, usage trigger, and a transparency note. No wasted words.

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?

Given only two parameters and no output schema, the description is largely complete: it covers purpose, usage timing, and behavioral transparency. The only gap is the unmentioned `bundle_dir` parameter meaning, which is inferable from context but not explicit.

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 schema describes `limit` but not `bundle_dir`. The description indirectly implies bundle_dir is the certificate directory but doesn't explicitly define it. This partial compensation for the 50% schema coverage is adequate but not thorough.

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 clearly states the tool explains why a certificate reached its verdict, listing specific outputs (safe/unsafe/straddling loci, margins, shortfalls). It also distinguishes from siblings by referencing verify_certificate and REJECT/REFUTED verdicts, making it unique among tools like explain_defect.

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?

The description explicitly states when to use it: 'Use this after verify_certificate returns REFUTED or a certificate records a REJECT.' It also explains the benefit ('turns an opaque refusal into a specific, actionable list'), leaving no ambiguity about its appropriate context.

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