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

Annotations already cover safety (readOnly, idempotent, non-destructive, closed-world), so the bar is lower. The description adds genuinely useful behavior: it returns multiple pattern-based options, annotates each with character length and approximate search-result truncation, and constrains generation to supplied answers only, which usefully rules out invented credentials. It does not say how many options are produced or whether the patterns are selectable.

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 single front-loaded sentence with the resource stated first, then the pattern list and the output traits. The parenthetical pattern enumeration with an ellipsis is slightly loose but each 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?

There is no output schema, so the description has to describe the return shape, and it does: multiple options, each labeled with a pattern, its length, and the search truncation point. The required role parameter and the "answers only" sourcing rule are covered. Minor gaps remain around option count and exact result formatting, but nothing essential to invoking the tool is missing.

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 documents all seven parameters with examples and lengths. The description adds no syntax or formatting detail beyond "the user's answers" and the pattern list, so the 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 and resource ("Write LinkedIn headline options") and goes further by naming the pattern families used (title+focus, title+result, title+who you help). An agent can immediately distinguish this generative tool from the sibling check_linkedin_headline, which audits an existing headline.

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 only implied: "from the user's answers" and the sibling name check_linkedin_headline make it inferable that this is the authoring counterpart to the checking tool. There is no explicit when-to-use, when-not-to-use, or named alternative (e.g. write_summary, check_linkedin_headline).

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