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

Beyond the annotations (readOnly, destructive=false), the description discloses important behavioral traits: nothing is saved, the article is not retitled, applying a title requires a separate update_article call, an API key is required, credits are consumed per call, and results are non-deterministic across repeated calls. It also mentions the 20-character minimum, which complements the schema.

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 concise yet complete, with each sentence earning its place: the first sentence states the core function, the second gives usage guidance, and the third covers side effects, requirements, and non-determinism. It is well-structured and front-loaded.

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 tool with a single parameter, strong annotations, and no output schema, the description covers all necessary dimensions: purpose, when to use, safety profile, side effects, prerequisites, and behavior. No critical information 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 coverage is 100% and the schema already describes the context parameter in detail (plain or Markdown, 20-8000 characters, more real draft yields better titles). The description repeats the 20-character minimum and adds no new meaning beyond the schema, so the baseline of 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?

The description clearly states the action ('Generate 5 title options') and the resource ('FROM AN EXISTING DRAFT'), and specifies the input source ('derived from what the article actually says'). It also differentiates from the sibling tool generate_title_seo by noting it takes no keyword input.

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?

Explicitly provides when-to-use guidance: 'use this one when the text exists and should drive the headline' and contrasts with generate_title_seo ('when you are starting from a topic or keyword'). It also states an exclusion: 'this tool takes no keyword input at all.'

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