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

Annotations already establish readOnly, idempotent, non-destructive behavior, so the description is only obligated to add context. It does so by disclosing that the response contains not just HTML but also installation instructions and France-specific legal mentions conditional on profession, useful behavior beyond the annotations.

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 dense sentences with no filler: purpose first, deliverables second, conditional behavior last. Every clause carries information.

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?

Since no output schema exists, the description correctly spends words on return contents (HTML, install steps, legal mentions). However, for a 24-parameter tool it leaves the bulk of parameter meaning and any invocation prerequisites unexplained, so it is only minimally complete.

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 24 parameters and only 46% schema description coverage, the description is expected to compensate but largely does not. It only hints at profession (triggering legal mentions) and the general notion of 'user's details'; the formatting, branding, font, image and address parameters are left entirely to the schema.

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?

Specific verb (Builds) plus concrete resource (a professional HTML email signature) with a compatibility scope (Gmail, Outlook, Apple Mail, Thunderbird) and a stated output. It does not name any sibling, though the profession/legal-mentions angle implicitly borders on get_profession_signature_rules.

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?

Usage is implied through 'from the user's details' and the conditional 'if a profession is given', but there is no explicit when-to-use statement, no prerequisite (e.g. that the profession value should come from list_professions), and no routing to get_install_instructions or check_email_domain.

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