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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds useful behavioral context beyond that: it restricts scope to a 'public' article, requires a 'canonical HTTPS' URL, and clarifies that output is cleaned 'readable body paragraphs' rather than raw markup. It does not discuss rate limits or paywalled content, but the added context is substantive.

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?

A single front-loaded sentence with zero waste; the extraction scope precedes the input requirement, so the agent gets the essential facts immediately.

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?

Output schema exists, annotations cover the safety profile, and the one parameter is fully documented, so the description need not explain return values. It is complete for the call, though a concrete URL format example would fully close the loop.

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?

With a single parameter at 100% schema description coverage, the schema already documents 'Canonical Phys.org article URL'. The description repeats the canonical-HTTPS requirement without adding format examples or validation details beyond the schema. Baseline 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?

States a specific verb (extract) and resource (metadata and readable body paragraphs from one Phys.org article), and clearly names the sibling scope distinction: this is for a single article rather than the physorg_headlines/news/sections list tools. An agent can identify the operation and target without opening the schema.

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 phrase 'one public Phys.org article' implies this is used when a specific article URL is in hand, but there is no explicit when-to-use vs. when-not guidance and no routing to siblings such as physorg_headlines for discovery. Usage is implied rather than stated.

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