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

No annotations are provided, so the description carries the full burden and does well: it discloses billing granularity ('per started 4 000 chars'), the exact price (€0.003), and that charges go against the API key in the Authorization Bearer header. It omits failure modes (invalid URL, oversized input) and any indication of response time limits.

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?

Front-loaded with purpose and variant enumeration, followed by billing and then a compact parameter glossary — every clause carries information. The single run-on opening sentence plus inline pricing makes it slightly dense to scan, but there is no 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?

An output schema exists, so return values need not be described, and pricing/auth/params are covered. However, with zero annotations and zero schema description coverage, an agent still lacks guidance on precedence when both text and url are supplied and on input size or error behavior, leaving gaps for a 5-param 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 0% and the schema has no enums, so the description is the sole source of parameter meaning — and it delivers: all five params are defined, the allowed value sets for length, format, and language are spelled out, and defaults (medium, paragraph, same as source) are stated. This adds substantial meaning beyond the bare 'type: string' fields.

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+resource ('Faithful summary of text or a URL') and enumerates the output variants (short/medium/long; paragraph/bullets/TL;DR), so the agent knows exactly what the tool produces. It does not explicitly differentiate from near-siblings like rewrite, translate, or url_to_markdown, which keeps it short of a 5.

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 clarifies that url is an 'alternative' to text, which resolves the main usage ambiguity of two optional input paths, and lists defaults so the agent knows it can omit parameters. It stops short of naming when to prefer a sibling tool (e.g., url_to_markdown for full extraction vs. summarization).

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