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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false. The description adds meaningful behavioral context beyond those annotations: results are estimates (meta.estimated: true), iterations are clamped to a specific range, and the simulation is the 'full sim.' This helps the agent understand the tool's stochastic nature and output characteristics.

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 well-structured with Args and Returns sections, and the first sentence immediately conveys the core purpose. It is slightly redundant because every parameter description is repeated from the schema, but the overall length is reasonable and the key information is front-loaded.

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?

The output schema exists and documents the return type, while annotations cover the read-only/idempotent safety profile. The description adds sufficient context by naming the exact returned fields and the estimated flag, plus the iteration clamping behavior. It doesn't cover error handling or invalid team codes, but that is not critical for 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. The description's Args section largely restates the schema text (team code, clamped iterations, optional seed) without adding new semantic depth. It provides a concrete example for team ('FRA') but otherwise adds no meaning beyond what the input schema already contains.

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 opening phrase 'Round-by-round survival probabilities for one team in the full sim' clearly identifies the specific verb (compute survival probabilities), resource (one team), and scope (full simulation). It also distinguishes itself from sibling tools like football_simulate_bracket and football_simulate_group by focusing on a single team's path rather than a whole tournament or group.

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 implies when to use this tool—when you need a single team's knockout-stage progression probabilities—but it never explicitly states when not to use it or names alternatives. There is no guidance comparing it to football_simulate_bracket or football_match_predictor, so the agent must infer the appropriate context from the tool name and phrasing.

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