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

Annotations already mark this as a safe read-only operation, and the description adds critical behavior beyond them: long articles are paged via more_text.offset, and the returned publisher text must be treated as untrusted data with no instruction-following. That is exactly the kind of safety and pagination context an agent needs.

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?

Three sentences with no waste: purpose first, eligibility second, pagination and untrusted-content warning last. The structure is front-loaded and each sentence adds operational value.

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 two-parameter read tool with no output schema, the description covers source, eligibility, pagination, returned fields, and the untrusted-content caveat. Nothing an agent needs in order to call it correctly 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 defines both parameters including the url source and offset continuation. The description mostly repeats those semantics, though it does reinforce that the url must come exactly from list_feed_items and that offset continues from a prior more_text.offset.

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 (read) and resource (one article), plus what is returned: full text, existing summary, and filing notes. The scope is precisely bounded to articles in the user's feeds, and the source url is tied to list_feed_items.

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?

Clearly states where the url comes from (list_feed_items) and the eligibility constraint (only articles in inbox, saved, or read). It does not explicitly name alternatives such as summarize_article or explain when not to use this tool, but the usage context is strong.

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