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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), so the description's job is to add context — and it does: it states the computation is exact rather than estimated, cites the same function used on Clear Tape's public page, and enumerates what comes back. It does not discuss accuracy limits or edge-case behavior (e.g. streak larger than trades), but the added provenance context is genuinely useful.

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 core computation is front-loaded in the first sentence and the return contract and disclaimer follow in order. The three-result enumeration is slightly dense but each clause carries information; there is little filler.

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 no output schema, the description compensates by describing the return payload (inputs echoed back, each result with its unit, the formula, and the page link). Combined with a fully documented input schema (including ranges and the lang enum), an agent has everything required to call and interpret this 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?

Schema description coverage is 100%, so the baseline is 3, but the description adds a meaningful modeling assumption not in the schema: that trades are independent and that the streak is evaluated over those independent trades. That framing matters for interpreting winRate and trades correctly and goes beyond the field-level docs.

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 names a specific verb and resource and enumerates the exact outputs: probability of at least one losing streak of a given length, expected longest streak, and the 95% bound. It is clearly distinct from sibling calculators like calculate_drawdown_recovery or calculate_kelly_criterion.

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?

Usage is only implied by the tool's subject matter (streak-risk planning for a given win rate and trade count). The description offers no when-to-use/when-not guidance and never names an alternative sibling calculator, so the agent must infer the context. The 'educational, not investment advice' line is a disclaimer rather than routing guidance.

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