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

No annotations exist beyond the title, so the description carries the full burden. It discloses a useful constraint (capped at 30,000 characters) and mentions style options, but doesn't describe behavior on exceeding the cap, output format details, or whether the operation is non-destructive.

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 three short sentences, front-loaded with the core purpose, and every clause adds value (function, style options, character limit). No redundancy or filler.

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 no output schema and only 3 parameters, the description covers the main usage, customization options, and a key constraint. It doesn't explain error handling for over-limit input, but this is arguably out of scope for such a lightweight tool.

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%, with each parameter already described. The description adds minor clarification (e.g., 'sentence count' maps to the 'lines' parameter), but most meaning is already conveyed by the schema, keeping the score at the baseline.

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 a specific verb and resource: 'Summarise text into a few sentences.' It distinguishes from sibling text tools like text_classify, text_extract, and text_translate by focusing specifically on summarization.

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?

Provides clear usage context by explaining how to customize output via style=bullets or a sentence count. Doesn't explicitly exclude alternatives, but among the text-processing siblings, summarization is a distinct function, making the intended use unambiguous.

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