Read a blog article

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

Annotations already declare readOnly, idempotent, non-destructive and open-world, so the safety profile is covered. The description adds genuinely new behavior: long articles are cut, a truncation flag signals it, and a url gives the full page — practical details an agent needs before deciding whether to increase max_chars.

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 short sentences with the purpose first and the truncation caveat second; nothing is repeated from the schema and every clause carries information the agent needs.

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?

Though there is no output schema, the description sketches the return shape (plain text, truncated flag, url) and the truncation semantics, which is everything needed to call a two-parameter read tool correctly. Nothing material is left unstated.

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 this is already baseline 3, but the description adds meaning beyond the schema: the consequence of max_chars (text is cut) and where the untruncated content lives (url). The id's provenance from kn_articles is also reinforced in prose.

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?

"Read one article of the Karnameh car magazine as plain text" states a specific verb (read), a single resource (one article), and the output format (plain text). The follow-up sentence anchors it against the sibling kn_articles, so an agent can tell list-vs-fetch apart without inspecting schemas.

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?

"Use after kn_articles" gives explicit sequencing guidance and implicitly names the alternative that produces the id. No when-not-to-use condition, but for a simple fetch tool the ordering hint is the essential guidance and it is stated plainly.

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