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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds rich behavioral context beyond annotations: tier-shaped response (Free/Builder/Pro), paywall metadata indicating withheld fields, 'no picks, no advice', and the found:false-with-reason behavior when no Flash provider exists. No contradiction with annotations.

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 a bit longer than necessary but every sentence earns its place: purpose, behavioral tiering, availability, missing-data behavior, and explicit usage guidance. It is front-loaded with the core purpose and ends with when-to/not-to-use. Minor redundancy exists ('Read-only. No side effects.' repeats annotations), but it does not detract significantly.

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 four parameters, no output schema, and annotations covering safety, this description covers everything an agent needs to decide whether and how to call: purpose, tier behavior, provider availability, missing-data behavior, and sibling differentiation. The paywall metadata note signals output shape despite the lack of an output schema. Nothing critical is missing.

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 coverage is 100%, so all four parameters already have descriptive entries in the input schema. The description does not add parameter-level semantics beyond what the schema provides; it focuses on tool-level behavior and tiering. Baseline 3 is appropriate because the schema does the heavy lifting.

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?

States a specific verb+resource: 'Assemble the whole story of a single prop in one call.' The title lists the exact contents (book line, Flash line, gap, form, splits, movement), and the 'When not to use' line explicitly distinguishes it from scan_props and get_player_context. An agent can clearly tell what this tool does and what it does not cover.

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?

Provides explicit 'When to use: explain one prop end-to-end' and 'When not to use: scan_props for broad discovery or get_player_context for a player overview.' It also gives an availability condition (registered Flash provider) that should determine whether the tool can be used, which is exactly the kind of routing guidance an agent needs.

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