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

Annotations already provide readOnlyHint: true. The description reinforces this with 'Read-only and free', adding the 'free' aspect which is not in annotations. It does not mention response limits or pagination, but the output schema likely covers structure. The behavioral context beyond annotations is adequate.

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?

The description is two sentences, front-loaded with purpose and value, followed by filtering guidance and pairing suggestion. Every sentence is essential, with no wasted words. Excellent conciseness.

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?

Given the tool has only two optional parameters, an output schema, and sibling context, the description is largely complete. It covers purpose, filtering, pairing, and safety (read-only). A slight gap is not explaining what 'velocity' means, but that is likely in the output schema. Overall very solid.

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 both parameters are documented. The description adds value for the category parameter ('Filter by category to focus a sector, or omit it for the overall board'), but does not elaborate on 'limit'. The added context for one parameter moves it slightly above baseline 3, but not enough to reach 4.

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 clearly states the tool shows 'startup categories that are trending right now and their velocity', providing a specific verb (Show) and resource. It distinguishes itself from siblings like get_sector_report by mentioning deeper drill-down, so the purpose is well-defined and unique.

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?

The description gives clear guidance on when to use: 'Filter by category to focus a sector, or omit it for the overall board' and pairs with get_sector_report for deeper analysis. It does not explicitly state when not to use it, but the context is sufficient. Minor improvement would be to exclude overlapping tools like get_market_signals.

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