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

Annotations already declare read-only, idempotent, non-destructive safety, and the description still adds real behavioral context: SSRF guarding, refusal of private addresses / non-HTML / error pages, that refusal happens before payment, and an explicit $0.005 cost. These are exactly the traits an agent needs and none of them come from structured fields.

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?

Two dense sentences, front-loaded with what is fetched and produced, followed by guardrails and price. Every clause (SSRF-guarded, bounded, before payment, cost) earns its place with zero 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?

With no output schema, the description usefully enumerates the returned fields (title, author, date, canonical URL, links, metadata), which is strong. It is slightly incomplete on how max_chars truncates output and on its relationship to get_page_metadata.

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 67% (url and links documented, max_chars not). The description lists "links" among outputs, loosely hinting at the links flag, but gives no guidance on max_chars or truncation behavior, so it neither compensates fully nor is empty. Baseline 3 fits.

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 states a specific verb+resource: fetch a public URL and extract main content as clean Markdown, even enumerating returned fields. However, it never distinguishes itself from the sibling get_page_metadata, which an agent could easily confuse with this tool.

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?

"Designed for agent research" and the refusal rules (private addresses, non-HTML, error pages) imply when it applies, but there is no explicit when-to-use versus when-not, and no named alternative such as get_page_metadata.

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