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

With no annotations provided, the description carries the full behavioral burden, and it does so thoroughly: it declares read-only/no side effects, API key requirement, tier-shaped response behavior, paywall metadata, no picks/advice, and the found:false failure mode with reasons. This goes far beyond what the schema alone reveals.

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 longer than one sentence but every sentence carries distinct value: core purpose, safety, tier behavior, failure mode, and usage guidance. It is front-loaded with the primary purpose and structured logically from general to specific. It could be slightly trimmed without loss, but it avoids redundancy and remains efficient.

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's complexity (tiering, provider availability, no output schema), the description covers the essential context: what the response contains per tier, how paywall withholding is communicated, failure behavior with found:false, and when to use alternatives. An agent has enough to decide whether and how to invoke this tool 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 description coverage is 100%, so the baseline is 3. The description does not add parameter-level detail beyond the schema, but the schema already documents each parameter's purpose (e.g., stat key, sport id, player name). The description's mention of 'player or gamertag' and 'event id to disambiguate' reinforces schema text without significantly adding new semantic meaning.

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 states a specific verb and resource: 'Assemble the whole story of a single prop in one call.' It clearly distinguishes this tool from siblings by focusing on one prop's complete evidence, differentiated from scan_props and get_player_context. The title reinforces the scope by enumerating the evidence components.

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 explicitly states 'When to use: explain one prop end-to-end. When not to use: scan_props for broad discovery or get_player_context for a player overview.' It also provides a conditional availability guideline about the Flash provider. These explicit routing instructions leave no ambiguity for an agent.

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