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

Beyond the annotations (readOnlyHint, idempotentHint), the description adds transparency by explaining the PARTIAL status as 'insufficient scoring history, reported honestly instead of guessed.' It also mentions the funding-stress overlay regime, providing behavioral context not captured in the schema.

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?

Three sentences, all value-dense: first defines the tool's content, second clarifies PARTIAL semantics, third gives usage guidance and alternative. No fluff or repetition.

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?

Despite no output schema, the description explains what the tool shows, the meaning of a key value, and how to get more detail via board_full. This is complete for a simple, read-only board view tool.

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?

With zero parameters, the description correctly focuses on the content rather than parameter syntax. The baseline for 0 params is 4, and the description adds value by enumerating the market segments covered, even though this isn't parameter-related.

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 identifies the tool as providing the Undertow board's tier row, listing the exact market segments (UST, IG, HY, EQUITY, ETF, FX, CN, CRYPTO, BSTOCK) and the funding-stress overlay. It distinguishes itself from the sibling 'board_full' tool by noting the difference between a quick glance and full measures.

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 states when to use this tool ('how liquid are markets today' at one glance) and provides alternatives: drill into crypto with other tools, or use the subscriber 'board_full' tool for every measure with stress percentile and analyst note.

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