Create free TLS certificate

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

Goes well beyond the annotations: it discloses the required certificates:manage permission, explains the key-custody consequence of managed mode (key is portal-only behind 2FA and never retrievable via MCP), and reinforces idempotency. These are exactly the behavioral facts an agent needs before a write operation.

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?

A tight four-sentence block that front-loads the purpose, then preconditions, then mode guidance, then permission. Every sentence earns its place, though it is dense enough that a small amount of condensed phrasing could be trimmed.

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?

For a 10-parameter, 6-required, enum-heavy write tool with no output schema, the description covers preconditions, key-custody tradeoffs, and permissions. The main gap is that it doesn't describe what the call returns or idempotency-key retry behavior, though the schema covers the key semantics.

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 the schema already explains every parameter including key_mode, csr, and delivery_method. The description's key_mode guidance ('use customer_csr for portable deployment', 'managed permits unattended renewal') largely restates what the schema already documents, so baseline 3 is appropriate.

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 (Create), resource (free public DV TLS certificate request), and key qualifiers (idempotent, no-cost, after preflight). This clearly distinguishes it from siblings like renew_free_certificate, cancel_free_certificate, and preflight_free_certificate, which the 'after preflight' clause implicitly references.

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?

Gives a strong, explicit precondition (call only after the user approves the exact DNS names, CA, validation/delivery method, and key-custody mode) and ties invocation to a prior preflight. It does not name the preflight tool or an alternative tool explicitly, so it stops short of full routing detail.

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