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

Annotations already cover the safety profile (readOnly, openWorld, non-destructive), and the description adds genuinely useful behavioral context: extractive TextRank, 50+ language support, and the explicit claim of no AI cost and no invented content. It does not cover rate limits or fetch failures on URLs, but adds real value beyond annotations.

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 opening two sentences ('Summarize a text or web page. Summarize a text or URL.') are near-duplicates that consume space without adding meaning. The rest is efficient, but the redundancy is real waste.

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 5-parameter tool with no required fields and no output schema, the description should clarify that the caller must supply text OR url; it merely implies this. It does cover output-side traits (keywords, reading time), which partly compensates.

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%, so the schema already documents all five parameters. The description corroborates the URL and language aspects but adds no syntax or interplay detail (e.g., how ratio and sentences interact). Baseline 3 applies.

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 names a specific verb+resource (summarize text/URL) and adds the mechanism (TextRank) and outputs (keywords, reading-time). It is distinguishable from siblings like extract_keywords or link_preview, though it never explicitly names them.

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?

There is no when-to-use or when-not-to-use guidance and no named alternatives, despite a crowded sibling set (extract_keywords, link_preview, spell_check). Usage is only implied by the verb.

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