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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world behavior. The description adds meaningful context beyond that: the output is Persian (fa-IR, RTL) text from public fekrestan.com pages, each item has a lead and live station count, and the scope excludes in-app exercise answers. It does not mention pagination or ordering, which would be useful for a list tool.

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, each carrying distinct information: returned fields, language/source/audience, and an explicit exclusion. It is front-loaded with the resource and payload, though it could state the listing action more directly at the start.

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 zero-parameter list tool with annotations covering safety, the description is largely complete: it explains the returned fields, language, source domain, audience, and one scope boundary. Missing are ordering, pagination, or result-size expectations, which would help an agent decide whether to call this versus search or get_subject.

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?

The tool takes zero parameters, so the baseline is 4. The description correctly adds no parameter information because none exist, and the schema is empty as expected.

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 identifies the resource as 'public learning tracks (subjects)' and specifies what each entry contains: a one-line lead, live station count, and subject page URL. It clearly separates this from a single-subject detail tool by emphasizing a list of tracks, though it never explicitly names get_subject as the alternative.

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?

Usage is implied by the list framing and the mention of parents and teachers, and the exclusion 'No answers to in-app exercises' rules out one misuse. However, there is no explicit instruction such as 'use get_subject for a single subject' or 'use this to browse the catalog,' leaving sibling selection to inference.

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