check_sender_requirements

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

No annotations exist, so the description carries full burden. It states the tool is read-only, uses a single GET, requires no auth, and returns per-requirement pass/fail/warning verdicts with cited rules. This adequately discloses behavior, though it could mention if there are any side effects or rate limits.

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?

Two sentences, no fluff. First sentence explains purpose and checks, second sentence gives usage context and alternative. Information density is high and front-loaded.

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?

The tool is simple (one required param, no output schema), and the description covers purpose, scope, and return format adequately. Missing minor details like potential error conditions, but overall sufficient.

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 (domain) with schema description covering 100%. The description adds no extra semantic detail beyond 'Domain name, e.g. example.com.' Baseline score is appropriate as schema does the work.

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 checks Google/Yahoo 2024 bulk-sender requirements and lists specific checks (SPF, DKIM, DMARC, etc.). It distinguishes from sibling check_email_security by specifying what this tool covers beyond that sibling.

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 'Use before sending bulk mail (5k+ messages/day to consumer providers)' and provides a clear alternative: 'use check_email_security for the broader read of SPF/DKIM/DMARC alone.' This gives direct when-to-use and when-not-to-use guidance.

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