resolve_spf_chain

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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false. The description adds valuable behavioral details beyond annotations: recursive resolution, output metrics (lookup count, tree depth), and detection of circular includes and the 10-lookup limit. This is more context than typical and aligns with the read-only nature.

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 two sentences long and front-loads the primary action. Every sentence adds substantive information (what it does, what it shows, and what it flags), with no waste or repetition.

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?

Without an output schema, the description explains the key output aspects (lookup count, tree depth, flags) and edge cases (circular includes, limit). It covers the core behavior adequately. It could mention output format or caching behavior (given force_refresh exists), but overall it gives enough context for an agent to understand the tool's capabilities.

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% (all three parameters have descriptions). The tool description provides no additional parameter-specific meaning beyond the schema. It mentions output characteristics but not parameter details, so the baseline 3 applies.

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's purpose: 'Trace the full SPF include chain for a domain.' It specifies the exact resource (SPF include chain) and the specific actions (recursively resolves includes, shows lookup count, tree depth, flags circular includes/limit). This distinguishes it from siblings like check_spf or check_dnssec_chain.

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 implies the use case: when you need to trace SPF includes and check for circular includes or lookup limits. However, it does not explicitly mention when not to use it or contrast with alternative tools like check_spf. The context is clear but lacks explicit exclusions or alternative references.

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