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

Goes well beyond the readOnly/openWorld annotations: it discloses that only the first page (up to 100 certificates) is returned, that at most 100 names are listed, how wildcards are rendered, and — critically — that the call costs $0.002 USDC via x402 on Base/Solana/Arc while failed calls are free. That cost signal is exactly what an agent needs before invoking.

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?

Front-loads the core output immediately, then limits, then pricing. Dense but every clause carries information; no filler sentences.

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?

An output schema exists, so return-shape explanation is optional, yet the description still summarizes the returned fields. With pricing, limits, and wildcard behavior covered, the only gap is competitive positioning against similar security/dns siblings.

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?

Only one parameter with 100% schema coverage, so the baseline of 3 applies. The description references the domain input but adds no format or edge-case guidance beyond what the schema already says.

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?

States a specific resource (subdomain names from public Certificate Transparency logs) and adds the source (CertSpotter) plus what is returned (issuers, latest issue date, valid-cert count). An agent can tell this apart from generic DNS or TLS tools, though no sibling is named explicitly.

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 must infer this is the tool for enumerating subdomains from CT logs. No exclusions or pointers to related siblings such as security_subdomain_takeover, security_dns_records, or security_ssl_cert_chain are given.

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