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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety and web-source profile is covered. The description's only added behavioral detail is that content comes from 'one verified public RSS feed,' which usefully signals a single bounded feed rather than open search, but nothing about freshness, pagination, or limits is given.

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 sentence, front-loaded with the action and resource, with the prerequisite clause second. Every phrase carries information and 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?

For a one-parameter read tool with an output schema and safety annotations already in place, the description covers the essentials: what is fetched, from where, and the required input source. Nothing critical for correct invocation is missing.

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%, and the schema already enumerates the documented slug values in full. The description only restates that the slug comes from physorg_sections, adding no syntax or format detail beyond the schema, so the 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 gives a specific verb (Fetch), resource (current Phys.org story cards), and scope (one verified public RSS feed), which tells the agent exactly what it retrieves. It stops short of naming the sibling tools it must not be confused with (physorg_news, physorg_article), so differentiation rests on the word 'story cards' alone.

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?

It states the prerequisite directly: the section argument must be a slug returned by physorg_sections, which sets up the correct call order. It does not explain when this tool is preferred over physorg_news or physorg_article, so no exclusions are offered.

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