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

Annotations mark it destructive/non-idempotent, and the description justifies and expands that: it warns a real submission sends a REAL e-mail to the form's recipient, and enumerates the outcome states (mail_sent, mail_failed incl. the SMTP-conversion consequence, validation_failed, spam). This adds substantial behavioral context beyond the structured hints.

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-loaded with the core purpose and the confirm/fields semantics before the outcome taxonomy. It is dense but every clause carries useful information; slightly long for a single paragraph but no filler.

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 an output schema exists, return values need not be documented, yet the description still characterizes the meaningful result states. Combined with the safety/behavioral disclosures, an agent has everything needed to invoke it correctly and safely.

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?

With 0% schema coverage the description must carry parameters, and it does well for the two subtle ones: fields is given the {'field-name':'value'} shape with auto-fill of omitted required fields, and confirm is fully explained. form_id is obvious from the name, but site_url is never mentioned, leaving a minor gap.

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+resource (submits a test entry to a Contact Form 7 form) and the exact mechanism (the plugin's REST endpoint), which distinguishes it from siblings like wordpress_contact_forms and site_form_submissions that list rather than submit. An agent knows precisely what the tool does.

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?

Clearly explains the two operational modes and when each applies: confirm=false only previews, confirm=true submits a real e-mail once. This is strong when-to-use guidance, though it does not name sibling alternatives (e.g., the real submission path) explicitly.

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