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

With no annotations, the description carries the burden and does well: it discloses that a missing board is fetched live by the handler, that rate limiting/quota exhaustion should be surfaced as a plan limit to the user, and that default sort is current rank. It stops short of describing auth/permission requirements or response shape, which keeps it from a 5.

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?

Front-loaded with purpose, then usage rules and exclusions. Each sentence carries information, though the category enumeration and country-type list overlap heavily with the schema, adding mild redundancy.

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 7-parameter, no-annotation, no-output-schema live-feed tool, the description covers routing, fallback behavior, and error/quota handling adequately. Return-value details are left to the schema's parameter text, which is acceptable.

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 description coverage is 100%, so the schema already documents sort, type, limit, offset, window, country, and category in detail. The description largely restates the schema's category rule and sort/window semantics, adding little syntax or format detail beyond it; 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?

Opens with a specific verb+resource+scope: 'Live top-trending board for exactly one feed type.' It distinguishes itself from siblings by explicitly naming get_growth and get_time_series as the tools for app history. An agent can route correctly without opening any 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?

Provides explicit when-to-use rules (always pass category for five named feed types), explicit exclusions ('Do not use get_time_series for live boards'), and names the alternatives for app history. The rate-limit/quota behavior instruction is also given.

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