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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is clear. The description adds value by explaining the signed decision model, that policies can only make decisions stricter, and the required agent token for robots.txt. It doesn't detail rate limits or auth requirements, but covers key behavioral aspects.

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 front-loaded with the most important instruction ('Call BEFORE...'), followed by outcome details and behavioral rules. It's efficient but slightly dense; each sentence earns its place, though it could be slightly more structured (e.g., bullet points for outcomes).

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 the tool's complexity (5 parameters, nested objects, policy logic), the description covers the essential: what it does, when to use, outcomes, and enforcement of policy. However, it doesn't explain the template parameter's purpose or the signed decision format in detail, leaving some gaps for a tool with no output schema.

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%, so all parameters (agent, action, domain, policy, template) are documented in the schema. The description adds context on the agent parameter ('Pass your crawler token as agent so robots.txt is checked') and mentions the policy constraint, but doesn't add significant meaning beyond the schema for the other parameters. Baseline 3 is appropriate when schema does heavy lifting.

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 verb (preflight check) with a clear resource (domain) and explicitly enumerates the possible outcomes (allow, warn, require_confirmation, block, unsupported). The opening 'Call BEFORE reading, citing, connecting to or transacting with a domain' makes its purpose distinct from siblings like resolve_domain or scan_domain.

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?

Explicitly says when to use it (before any domain interaction) and provides conditional guidance for acting on results: 'Do not proceed on block; ask the user on require_confirmation.' It also mentions passing a crawler token for robots.txt checks. This gives both when-to-use and how-to-respond guidance.

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