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

Annotations already declare readOnly, idempotent, openWorld and non-destructive, so the safety profile is covered. The description adds genuinely useful non-annotation context: ranks are one-based and internal heat scores are deliberately excluded from the response, which prevents an agent from hunting for a field that does not exist.

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 tight sentences with zero filler; the primary retrieval purpose is front-loaded and the sibling routing and response caveat follow in priority order.

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 single-parameter, no-output-schema read tool, the description supplies the essential retrieval semantics (Top 10, one-based rank, heat scores omitted) and the routing to siblings. Only minor details such as the shape of each event entry are left unstated, which is acceptable at this complexity.

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?

Only one parameter and schema coverage is 100%, with the min/max/default fully documented in the schema. The description adds nothing about the limit parameter beyond the implicit 'Top 10' framing, 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 states a specific verb and resource ('Get the current BITHOT Top 10') plus the returned detail (one-based rank), and explicitly contrasts with the sibling bithot_get_latest. An agent can distinguish this from the daily/weekly/monthly/chronological siblings without opening a schema.

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?

Gives an explicit use case ('what is hot now') and a second one (discovering valid story public IDs), then names the alternative tool and the condition that selects it ('use bithot_get_latest for a chronological news list'). This is exactly the when/when-not/alternative pattern.

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