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 useful content scope by enumerating the fields returned (verified revenue/MRR, traffic, growth, tech stack, marketplace fields), which goes beyond the annotations.

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 waste, and the core purpose is front-loaded ahead of the sibling routing note.

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 get-by-id tool with an output schema present, the description covers purpose, dataset identity, sibling routing, and a field summary. An agent has everything needed to call it correctly.

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 itself documents the slug with an example ('gumroad'). The description says 'by slug' but adds no format or syntax detail beyond what the schema already provides, so 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?

States a specific verb and resource: 'Returns one startup record by slug from the TrustMRR dataset'. The singular 'one startup record by slug' cleanly distinguishes it from sibling retrieval tools like datasets_trustmrr_search.

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?

Explicitly routes the agent to datasets_trustmrr_search for searching the dataset, implying this tool is for direct lookup by slug. It names the alternative but does not spell out the selection condition (i.e., use this only when you already have the slug).

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