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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds genuine behavioral context beyond that: the result is capped at a fixed top 100 and is a comparative ranking rather than a per-listing lookup. It does not mention pagination or refresh cadence, keeping it just short of 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?

Two sentences, zero filler, and the core capability is front-loaded ahead of the routing guidance to sibling tools.

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 an output schema present, return values need no explanation, and the single optional parameter is fully documented in the schema. The description supplies purpose, scope, and alternative routing, leaving only minor gaps such as whether results are refreshable or time-scoped.

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% and the metric parameter's allowed values (mrr, last_30_days_revenue, all_time_revenue, growth, traffic, revenue_per_visitor) are fully enumerated in the schema. The description only echoes 'selected public revenue metric,' adding no syntax or format detail beyond the schema, 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 gives a specific verb ('List') and resource ('top 100 startup ranking rows'), plus the scoping qualifier 'for a selected public revenue metric.' It also names the sibling tools it is not, so an agent can distinguish it from trustmrr_startups/trustmrr_marketplace 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?

It explicitly states when to prefer the alternatives: use trustmrr_startups or trustmrr_marketplace to 'discover individual listings rather than compare the ranked leaderboard.' Both the alternative tools and the selecting condition are spelled out.

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