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

Annotations already declare read-only, idempotent, closed-world and non-destructive, so the safety profile is covered. The description adds genuinely new context: content comes from public site pages, is Persian fa-IR RTL, and bundles author, reviewer, dates and cited sources, which tells an agent what to expect from the response shape.

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 short sentences, front-loaded with what is returned, then locale/provenance, then the exclusion. No filler and nothing repeated from the schema.

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 compensates by enumerating the return fields (Markdown text, author, reviewer, dates, cited sources, related articles) and the language/format. For a single-parameter read tool this leaves nothing an agent needs 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 explains the slug format and that it comes from search_articles. The description adds no further constraint or formatting guidance on the slug, so the 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 resource and cardinality ('One published parent article') plus the payload it returns, which separates it from list-style siblings like search_articles and list_subjects. The closing exclusion ('No answers to in-app exercises') further fences it off from the how-to-solve tools.

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 audience and domain ('public fekrestan.com pages for parents and teachers') and the explicit exclusion of in-app exercise answers give a clear picture of when this tool applies. The schema's 'Article slug from search_articles' implies the search-then-fetch workflow, but the description itself never names an alternative tool for out-of-scope requests.

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