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

Annotations provide only readOnlyHint=true. The description adds behavioral context by stating it's 'free, AI-generated, rate-limited,' which informs the agent about pricing, generation nature, and rate limits. This aligns with the annotation and adds value beyond it.

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?

The description is efficient—one core sentence plus a parenthetical. It front-loads the main action. Slight redundancy exists in the 'Paragraph Generator:' prefix which repeats the title, but the rest is concise.

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 simple tool with two parameters and no output schema, the description adequately covers what the tool does, the input type, and a key constraint (rate limit). It doesn't describe the exact response format, but given the simplicity and readOnlyHint, this is 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?

Schema coverage is only 50% (tone has a description, topic does not). The description clarifies the primary parameter 'topic' by explaining it can be a topic or sentence to expand, but it does not elaborate on the optional 'tone' parameter or its accepted values. It adds some meaning but doesn't fully compensate for the coverage 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?

The description uses a specific verb 'Expand' and specifies the resource 'a topic or sentence into a well-written paragraph,' clearly distinguishing it from sibling generators (e.g., ad-copy, headline, blog-outline). It states the exact output type.

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?

The description clearly implies usage context: when you have a topic or sentence and need a well-written paragraph. However, it does not explicitly name alternative tools or exclusions, so it lacks the explicit differentiation seen in higher-scoring examples.

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